164402621 has 2 divisors, whose sum is σ = 164402622. Its totient is φ = 164402620.

The previous prime is 164402599. The next prime is 164402627. The reversal of 164402621 is 126204461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 164121721 + 280900 = 12811^2 + 530^2 .

It is an emirp because it is prime and its reverse (126204461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 164402621 - 2¹⁴ = 164386237 is a prime.

It is a super-3 number, since 3×164402621³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (164402627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82201310 + 82201311.

It is an arithmetic number, because the mean of its divisors is an integer number (82201311).

Almost surely, 2^164402621 is an apocalyptic number.

It is an amenable number.

164402621 is a deficient number, since it is larger than the sum of its proper divisors (1).

164402621 is an equidigital number, since it uses as much as digits as its factorization.

164402621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 164402621 is about 12821.9585477414. The cubic root of 164402621 is about 547.8179339499.

The spelling of 164402621 in words is "one hundred sixty-four million, four hundred two thousand, six hundred twenty-one".