155691520 has 80 divisors (see below), whose sum is σ = 379794888. Its totient is φ = 61194240.

The previous prime is 155691511. The next prime is 155691563. The reversal of 155691520 is 25196551.

It can be written as a sum of positive squares in 4 ways, for example, as 111175936 + 44515584 = 10544^2 + 6672^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 155662 + ... + 156658.

Almost surely, 2^155691520 is an apocalyptic number.

155691520 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 155691520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (189897444).

155691520 is an abundant number, since it is smaller than the sum of its proper divisors (224103368).

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

155691520 is an frugal number, since it uses more digits than its factorization.

155691520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1081 (or 1065 counting only the distinct ones).

The product of its (nonzero) digits is 13500, while the sum is 34.

The square root of 155691520 is about 12477.6408026518. The cubic root of 155691520 is about 537.9661951369.

The spelling of 155691520 in words is "one hundred fifty-five million, six hundred ninety-one thousand, five hundred twenty".