164831981 has 2 divisors, whose sum is σ = 164831982. Its totient is φ = 164831980.

The previous prime is 164831977. The next prime is 164832001. The reversal of 164831981 is 189138461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 147233956 + 17598025 = 12134^2 + 4195^2 .

It is a cyclic number.

It is not a de Polignac number, because 164831981 - 2² = 164831977 is a prime.

It is a super-2 number, since 2×164831981² = 54339163920768722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (164831921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82415990 + 82415991.

It is an arithmetic number, because the mean of its divisors is an integer number (82415991).

Almost surely, 2^164831981 is an apocalyptic number.

It is an amenable number.

164831981 is a deficient number, since it is larger than the sum of its proper divisors (1).

164831981 is an equidigital number, since it uses as much as digits as its factorization.

164831981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 41472, while the sum is 41.

The square root of 164831981 is about 12838.6907821631. The cubic root of 164831981 is about 548.2944199516.

The spelling of 164831981 in words is "one hundred sixty-four million, eight hundred thirty-one thousand, nine hundred eighty-one".