165998979 has 12 divisors (see below), whose sum is σ = 239888376. Its totient is φ = 110614272.

The previous prime is 165998977. The next prime is 165998993. The reversal of 165998979 is 979899561.

165998979 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 165998979 - 2¹ = 165998977 is a prime.

It is a super-2 number, since 2×165998979² = 55111322058084882, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (165998977) 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, 33187 + ... + 37859.

It is an arithmetic number, because the mean of its divisors is an integer number (19990698).

Almost surely, 2^165998979 is an apocalyptic number.

165998979 is a deficient number, since it is larger than the sum of its proper divisors (73889397).

165998979 is a wasteful number, since it uses less digits than its factorization.

165998979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8626 (or 8623 counting only the distinct ones).

The product of its digits is 11022480, while the sum is 63.

The square root of 165998979 is about 12884.0591041799. The cubic root of 165998979 is about 549.5853392446.

It can be divided in two parts, 16 and 5998979, that added together give a palindrome (5998995).

The spelling of 165998979 in words is "one hundred sixty-five million, nine hundred ninety-eight thousand, nine hundred seventy-nine".