621610415221 has 2 divisors, whose sum is σ = 621610415222. Its totient is φ = 621610415220.

The previous prime is 621610415201. The next prime is 621610415243. The reversal of 621610415221 is 122514016126.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 342007414596 + 279603000625 = 584814^2 + 528775^2 .

It is a cyclic number.

It is not a de Polignac number, because 621610415221 - 2⁵ = 621610415189 is a prime.

It is a super-2 number, since 2×621610415221² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (621610415201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310805207610 + 310805207611.

It is an arithmetic number, because the mean of its divisors is an integer number (310805207611).

Almost surely, 2^621610415221 is an apocalyptic number.

It is an amenable number.

621610415221 is a deficient number, since it is larger than the sum of its proper divisors (1).

621610415221 is an equidigital number, since it uses as much as digits as its factorization.

621610415221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5760, while the sum is 31.

The spelling of 621610415221 in words is "six hundred twenty-one billion, six hundred ten million, four hundred fifteen thousand, two hundred twenty-one".