621122674166921 has 2 divisors, whose sum is σ = 621122674166922. Its totient is φ = 621122674166920.

The previous prime is 621122674166899. The next prime is 621122674166927. The reversal of 621122674166921 is 129661476221126.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 338799978510400 + 282322695656521 = 18406520^2 + 16802461^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-621122674166921 is a prime.

It is a super-2 number, since 2×621122674166921² (a number of 30 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (621122674166927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310561337083460 + 310561337083461.

It is an arithmetic number, because the mean of its divisors is an integer number (310561337083461).

Almost surely, 2^{621122674166921} is an apocalyptic number.

It is an amenable number.

621122674166921 is a deficient number, since it is larger than the sum of its proper divisors (1).

621122674166921 is an equidigital number, since it uses as much as digits as its factorization.

621122674166921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5225472, while the sum is 56.

The spelling of 621122674166921 in words is "six hundred twenty-one trillion, one hundred twenty-two billion, six hundred seventy-four million, one hundred sixty-six thousand, nine hundred twenty-one".