155121120 has 288 divisors, whose sum is σ = 660441600. Its totient is φ = 32209920.

The previous prime is 155121119. The next prime is 155121121. The reversal of 155121120 is 21121551.

155121120 is a `hidden beast` number, since 1 + 551 + 2 + 112 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (155121119) and next prime (155121121).

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 155121093 and 155121102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155121121) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 110181 + ... + 111579.

It is an arithmetic number, because the mean of its divisors is an integer number (2293200).

Almost surely, 2^155121120 is an apocalyptic number.

155121120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 155121120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (330220800).

155121120 is an abundant number, since it is smaller than the sum of its proper divisors (505320480).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

155121120 is a wasteful number, since it uses less digits than its factorization.

155121120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1438 (or 1427 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 18.

The square root of 155121120 is about 12454.7629443519. The cubic root of 155121120 is about 537.3084170289.

Adding to 155121120 its reverse (21121551), we get a palindrome (176242671).

The spelling of 155121120 in words is "one hundred fifty-five million, one hundred twenty-one thousand, one hundred twenty".