164493991 has 2 divisors, whose sum is σ = 164493992. Its totient is φ = 164493990.

The previous prime is 164493929. The next prime is 164494013. The reversal of 164493991 is 199394461.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 164493991 - 2⁷ = 164493863 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (164493491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82246995 + 82246996.

It is an arithmetic number, because the mean of its divisors is an integer number (82246996).

Almost surely, 2^164493991 is an apocalyptic number.

164493991 is a deficient number, since it is larger than the sum of its proper divisors (1).

164493991 is an equidigital number, since it uses as much as digits as its factorization.

164493991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 209952, while the sum is 46.

The square root of 164493991 is about 12825.5210810321. The cubic root of 164493991 is about 547.9194020293.

The spelling of 164493991 in words is "one hundred sixty-four million, four hundred ninety-three thousand, nine hundred ninety-one".