621442644 has 24 divisors (see below), whose sum is σ = 1459768800. Its totient is φ = 205756704.

The previous prime is 621442631. The next prime is 621442651. The reversal of 621442644 is 446244126.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 171994 + ... + 175569.

It is an arithmetic number, because the mean of its divisors is an integer number (60823700).

Almost surely, 2^621442644 is an apocalyptic number.

It is an amenable number.

621442644 is an abundant number, since it is smaller than the sum of its proper divisors (838326156).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

621442644 is a wasteful number, since it uses less digits than its factorization.

621442644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 347719 (or 347717 counting only the distinct ones).

The product of its digits is 36864, while the sum is 33.

The square root of 621442644 is about 24928.7513526049. The cubic root of 621442644 is about 853.3627544516.

The spelling of 621442644 in words is "six hundred twenty-one million, four hundred forty-two thousand, six hundred forty-four".