155121140 has 12 divisors (see below), whose sum is σ = 325754436. Its totient is φ = 62048448.

The previous prime is 155121133. The next prime is 155121143. The reversal of 155121140 is 41121551.

It can be written as a sum of positive squares in 2 ways, for example, as 19678096 + 135443044 = 4436^2 + 11638^2 .

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 7756057 = 155121140 / (1 + 5 + 5 + 1 + 2 + 1 + 1 + 4 + 0).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155121143) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3878009 + ... + 3878048.

It is an arithmetic number, because the mean of its divisors is an integer number (27146203).

Almost surely, 2^155121140 is an apocalyptic number.

155121140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

155121140 is an abundant number, since it is smaller than the sum of its proper divisors (170633296).

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

155121140 is a wasteful number, since it uses less digits than its factorization.

155121140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7756066 (or 7756064 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 20.

The square root of 155121140 is about 12454.7637472575. The cubic root of 155121140 is about 537.3084401209.

Adding to 155121140 its reverse (41121551), we get a palindrome (196242691).

The spelling of 155121140 in words is "one hundred fifty-five million, one hundred twenty-one thousand, one hundred forty".