164955981 has 16 divisors (see below), whose sum is σ = 237276864. Its totient is φ = 101547264.

The previous prime is 164955971. The next prime is 164956003. The reversal of 164955981 is 189559461.

164955981 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 164955981 - 2¹⁷ = 164824909 is a prime.

It is a super-2 number, since 2×164955981² = 54420951335344722, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 164955981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (164955941) 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, 27811 + ... + 33216.

It is an arithmetic number, because the mean of its divisors is an integer number (14829804).

Almost surely, 2^164955981 is an apocalyptic number.

It is an amenable number.

164955981 is a deficient number, since it is larger than the sum of its proper divisors (72320883).

164955981 is a wasteful number, since it uses less digits than its factorization.

164955981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61100.

The product of its digits is 388800, while the sum is 48.

The square root of 164955981 is about 12843.5190271203. The cubic root of 164955981 is about 548.4318760164.

It can be divided in two parts, 1649 and 55981, that added together give a triangular number (57630 = T₃₃₉).

The spelling of 164955981 in words is "one hundred sixty-four million, nine hundred fifty-five thousand, nine hundred eighty-one".