164626421 has 2 divisors, whose sum is σ = 164626422. Its totient is φ = 164626420.

The previous prime is 164626411. The next prime is 164626447. The reversal of 164626421 is 124626461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 108451396 + 56175025 = 10414^2 + 7495^2 .

It is an emirp because it is prime and its reverse (124626461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 164626421 - 2²² = 160432117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (164626411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82313210 + 82313211.

It is an arithmetic number, because the mean of its divisors is an integer number (82313211).

Almost surely, 2^164626421 is an apocalyptic number.

It is an amenable number.

164626421 is a deficient number, since it is larger than the sum of its proper divisors (1).

164626421 is an equidigital number, since it uses as much as digits as its factorization.

164626421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13824, while the sum is 32.

The square root of 164626421 is about 12830.6827955491. The cubic root of 164626421 is about 548.0664013256.

The spelling of 164626421 in words is "one hundred sixty-four million, six hundred twenty-six thousand, four hundred twenty-one".