165135551 has 16 divisors (see below), whose sum is σ = 194602560. Its totient is φ = 137168640.

The previous prime is 165135547. The next prime is 165135559. The reversal of 165135551 is 155531561.

It is not a de Polignac number, because 165135551 - 2² = 165135547 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165135559) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 71645 + ... + 73913.

It is an arithmetic number, because the mean of its divisors is an integer number (12162660).

Almost surely, 2^165135551 is an apocalyptic number.

165135551 is a deficient number, since it is larger than the sum of its proper divisors (29467009).

165135551 is a wasteful number, since it uses less digits than its factorization.

165135551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2594.

The product of its digits is 11250, while the sum is 32.

The square root of 165135551 is about 12850.5078109777. The cubic root of 165135551 is about 548.6308102965.

The spelling of 165135551 in words is "one hundred sixty-five million, one hundred thirty-five thousand, five hundred fifty-one".