621616664 has 8 divisors (see below), whose sum is σ = 1165531260. Its totient is φ = 310808328.

The previous prime is 621616663. The next prime is 621616693. The reversal of 621616664 is 466616126.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621616663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38851034 + ... + 38851049.

Almost surely, 2^621616664 is an apocalyptic number.

It is an amenable number.

621616664 is a deficient number, since it is larger than the sum of its proper divisors (543914596).

621616664 is a wasteful number, since it uses less digits than its factorization.

621616664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77702089 (or 77702085 counting only the distinct ones).

The product of its digits is 62208, while the sum is 38.

The square root of 621616664 is about 24932.2414555932. The cubic root of 621616664 is about 853.4424015591.

The spelling of 621616664 in words is "six hundred twenty-one million, six hundred sixteen thousand, six hundred sixty-four".