165949881 has 16 divisors (see below), whose sum is σ = 224112000. Its totient is φ = 109219968.

The previous prime is 165949877. The next prime is 165949897. The reversal of 165949881 is 188949561.

165949881 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 165949881 - 2² = 165949877 is a prime.

It is a super-2 number, since 2×165949881² = 55078726007828322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (165949841) 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, 80775 + ... + 82803.

It is an arithmetic number, because the mean of its divisors is an integer number (14007000).

Almost surely, 2^165949881 is an apocalyptic number.

It is an amenable number.

165949881 is a deficient number, since it is larger than the sum of its proper divisors (58162119).

165949881 is a wasteful number, since it uses less digits than its factorization.

165949881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2368.

The product of its digits is 622080, while the sum is 51.

The square root of 165949881 is about 12882.1535854841. The cubic root of 165949881 is about 549.5311497511.

The spelling of 165949881 in words is "one hundred sixty-five million, nine hundred forty-nine thousand, eight hundred eighty-one".