641164021 has 2 divisors, whose sum is σ = 641164022. Its totient is φ = 641164020.

The previous prime is 641164001. The next prime is 641164039. The reversal of 641164021 is 120461146.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 639381796 + 1782225 = 25286^2 + 1335^2 .

It is a cyclic number.

It is not a de Polignac number, because 641164021 - 2¹³ = 641155829 is a prime.

It is a super-2 number, since 2×641164021² = 822182603649776882, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (641164001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320582010 + 320582011.

It is an arithmetic number, because the mean of its divisors is an integer number (320582011).

Almost surely, 2^641164021 is an apocalyptic number.

It is an amenable number.

641164021 is a deficient number, since it is larger than the sum of its proper divisors (1).

641164021 is an equidigital number, since it uses as much as digits as its factorization.

641164021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 641164021 is about 25321.2168151533. The cubic root of 641164021 is about 862.2960194234.

The spelling of 641164021 in words is "six hundred forty-one million, one hundred sixty-four thousand, twenty-one".