165136521 has 32 divisors (see below), whose sum is σ = 259780608. Its totient is φ = 92176640.

The previous prime is 165136519. The next prime is 165136523. The reversal of 165136521 is 125631561.

165136521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (165136519) and next prime (165136523).

It is a cyclic number.

It is not a de Polignac number, because 165136521 - 2¹ = 165136519 is a prime.

It is not an unprimeable number, because it can be changed into a prime (165136523) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 23236 + ... + 29498.

It is an arithmetic number, because the mean of its divisors is an integer number (8118144).

Almost surely, 2^165136521 is an apocalyptic number.

165136521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

165136521 is a deficient number, since it is larger than the sum of its proper divisors (94644087).

165136521 is a wasteful number, since it uses less digits than its factorization.

165136521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6341.

The product of its digits is 5400, while the sum is 30.

The square root of 165136521 is about 12850.5455526215. The cubic root of 165136521 is about 548.6318845066.

The spelling of 165136521 in words is "one hundred sixty-five million, one hundred thirty-six thousand, five hundred twenty-one".