155074921 has 4 divisors (see below), whose sum is σ = 155878612. Its totient is φ = 154271232.

The previous prime is 155074897. The next prime is 155074937. The reversal of 155074921 is 129470551.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 51768025 + 103306896 = 7195^2 + 10164^2 .

It is a cyclic number.

It is not a de Polignac number, because 155074921 - 2¹¹ = 155072873 is a prime.

It is a super-2 number, since 2×155074921² = 48096462246312482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155074991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 401556 + ... + 401941.

It is an arithmetic number, because the mean of its divisors is an integer number (38969653).

Almost surely, 2^155074921 is an apocalyptic number.

It is an amenable number.

155074921 is a deficient number, since it is larger than the sum of its proper divisors (803691).

155074921 is an equidigital number, since it uses as much as digits as its factorization.

155074921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 803690.

The product of its (nonzero) digits is 12600, while the sum is 34.

The square root of 155074921 is about 12452.9081342472. The cubic root of 155074921 is about 537.2550703789.

The spelling of 155074921 in words is "one hundred fifty-five million, seventy-four thousand, nine hundred twenty-one".