621616663 has 2 divisors, whose sum is σ = 621616664. Its totient is φ = 621616662.

The previous prime is 621616649. The next prime is 621616693. The reversal of 621616663 is 366616126.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 621616663 - 2²⁹ = 84745751 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (621616603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310808331 + 310808332.

It is an arithmetic number, because the mean of its divisors is an integer number (310808332).

Almost surely, 2^621616663 is an apocalyptic number.

621616663 is a deficient number, since it is larger than the sum of its proper divisors (1).

621616663 is an equidigital number, since it uses as much as digits as its factorization.

621616663 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46656, while the sum is 37.

The square root of 621616663 is about 24932.2414355388. The cubic root of 621616663 is about 853.4424011015.

The spelling of 621616663 in words is "six hundred twenty-one million, six hundred sixteen thousand, six hundred sixty-three".