165698981 has 16 divisors (see below), whose sum is σ = 200793600. Its totient is φ = 133569648.

The previous prime is 165698957. The next prime is 165699013. The reversal of 165698981 is 189896561.

165698981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 165698981 - 2¹⁸ = 165436837 is a prime.

It is a super-2 number, since 2×165698981² = 54912304608876722, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165692981) 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, 14006 + ... + 22968.

It is an arithmetic number, because the mean of its divisors is an integer number (12549600).

Almost surely, 2^165698981 is an apocalyptic number.

It is an amenable number.

165698981 is a deficient number, since it is larger than the sum of its proper divisors (35094619).

165698981 is a wasteful number, since it uses less digits than its factorization.

165698981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9128.

The product of its digits is 933120, while the sum is 53.

The square root of 165698981 is about 12872.4116233129. The cubic root of 165698981 is about 549.2540642665.

The spelling of 165698981 in words is "one hundred sixty-five million, six hundred ninety-eight thousand, nine hundred eighty-one".