641195021 has 2 divisors, whose sum is σ = 641195022. Its totient is φ = 641195020.

The previous prime is 641194999. The next prime is 641195053. The reversal of 641195021 is 120591146.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 453093796 + 188101225 = 21286^2 + 13715^2 .

It is a cyclic number.

It is not a de Polignac number, because 641195021 - 2²² = 637000717 is a prime.

It is a super-2 number, since 2×641195021² = 822262109910380882, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (641105021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320597510 + 320597511.

It is an arithmetic number, because the mean of its divisors is an integer number (320597511).

Almost surely, 2^641195021 is an apocalyptic number.

It is an amenable number.

641195021 is a deficient number, since it is larger than the sum of its proper divisors (1).

641195021 is an equidigital number, since it uses as much as digits as its factorization.

641195021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 29.

The square root of 641195021 is about 25321.8289426337. The cubic root of 641195021 is about 862.3099164112.

The spelling of 641195021 in words is "six hundred forty-one million, one hundred ninety-five thousand, twenty-one".