155157121 has 4 divisors (see below), whose sum is σ = 177322432. Its totient is φ = 132991812.

The previous prime is 155157089. The next prime is 155157133. The reversal of 155157121 is 121751551.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 155157121 - 2⁵ = 155157089 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 155157121.

It is not an unprimeable number, because it can be changed into a prime (155157421) 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, 11082645 + ... + 11082658.

It is an arithmetic number, because the mean of its divisors is an integer number (44330608).

Almost surely, 2^155157121 is an apocalyptic number.

It is an amenable number.

155157121 is a deficient number, since it is larger than the sum of its proper divisors (22165311).

155157121 is an equidigital number, since it uses as much as digits as its factorization.

155157121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22165310.

The product of its digits is 1750, while the sum is 28.

The square root of 155157121 is about 12456.2081308880. The cubic root of 155157121 is about 537.3499805591.

The spelling of 155157121 in words is "one hundred fifty-five million, one hundred fifty-seven thousand, one hundred twenty-one".