621616646 has 24 divisors (see below), whose sum is σ = 1087248096. Its totient is φ = 265770960.

The previous prime is 621616627. The next prime is 621616649. The reversal of 621616646 is 646616126.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621616649) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 34880 + ... + 49596.

It is an arithmetic number, because the mean of its divisors is an integer number (45302004).

Almost surely, 2^621616646 is an apocalyptic number.

621616646 is a deficient number, since it is larger than the sum of its proper divisors (465631450).

621616646 is a wasteful number, since it uses less digits than its factorization.

621616646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15164 (or 15157 counting only the distinct ones).

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

The square root of 621616646 is about 24932.2410946148. The cubic root of 621616646 is about 853.4423933215.

The spelling of 621616646 in words is "six hundred twenty-one million, six hundred sixteen thousand, six hundred forty-six".