155220000 has 240 divisors, whose sum is σ = 551073600. Its totient is φ = 38016000.

The previous prime is 155219993. The next prime is 155220017. The reversal of 155220000 is 22551.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 779901 + ... + 780099.

It is an arithmetic number, because the mean of its divisors is an integer number (2296140).

Almost surely, 2^155220000 is an apocalyptic number.

155220000 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 155220000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (275536800).

155220000 is an abundant number, since it is smaller than the sum of its proper divisors (395853600).

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

155220000 is a wasteful number, since it uses less digits than its factorization.

155220000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245 (or 222 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 15.

The square root of 155220000 is about 12458.7318776832. The cubic root of 155220000 is about 537.4225596023.

Adding to 155220000 its reverse (22551), we get a palindrome (155242551).

The spelling of 155220000 in words is "one hundred fifty-five million, two hundred twenty thousand".