621963066721 has 4 divisors (see below), whose sum is σ = 622099796500. Its totient is φ = 621826336944.

The previous prime is 621963066713. The next prime is 621963066727. The reversal of 621963066721 is 127660369126.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 296196089121 + 325766977600 = 544239^2 + 570760^2 .

It is a cyclic number.

It is not a de Polignac number, because 621963066721 - 2³ = 621963066713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (621963066727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68358066 + ... + 68367163.

It is an arithmetic number, because the mean of its divisors is an integer number (155524949125).

Almost surely, 2^621963066721 is an apocalyptic number.

It is an amenable number.

621963066721 is a deficient number, since it is larger than the sum of its proper divisors (136729779).

621963066721 is a wasteful number, since it uses less digits than its factorization.

621963066721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136729778.

The product of its (nonzero) digits is 979776, while the sum is 49.

The spelling of 621963066721 in words is "six hundred twenty-one billion, nine hundred sixty-three million, sixty-six thousand, seven hundred twenty-one".