165152421 has 12 divisors (see below), whose sum is σ = 272632672. Its totient is φ = 94372776.

The previous prime is 165152371. The next prime is 165152447. The reversal of 165152421 is 124251561.

165152421 is a `hidden beast` number, since 1 + 651 + 5 + 2 + 4 + 2 + 1 = 666.

It is not a de Polignac number, because 165152421 - 2⁶ = 165152357 is a prime.

It is a super-2 number, since 2×165152421² = 54550644324322482, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165150421) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1310671 + ... + 1310796.

Almost surely, 2^165152421 is an apocalyptic number.

It is an amenable number.

165152421 is a deficient number, since it is larger than the sum of its proper divisors (107480251).

165152421 is a wasteful number, since it uses less digits than its factorization.

165152421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2621480 (or 2621477 counting only the distinct ones).

The product of its digits is 2400, while the sum is 27.

The square root of 165152421 is about 12851.1641885084. The cubic root of 165152421 is about 548.6494920937.

The spelling of 165152421 in words is "one hundred sixty-five million, one hundred fifty-two thousand, four hundred twenty-one".