621645044 has 24 divisors (see below), whose sum is σ = 1141257600. Its totient is φ = 295873760.

The previous prime is 621645019. The next prime is 621645049. The reversal of 621645044 is 440546126.

It is a self number, because there is not a number n which added to its sum of digits gives 621645044.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621645049) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29504 + ... + 45975.

It is an arithmetic number, because the mean of its divisors is an integer number (47552400).

Almost surely, 2^621645044 is an apocalyptic number.

It is an amenable number.

621645044 is a deficient number, since it is larger than the sum of its proper divisors (519612556).

621645044 is a wasteful number, since it uses less digits than its factorization.

621645044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75583 (or 75581 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 32.

The square root of 621645044 is about 24932.8105916682. The cubic root of 621645044 is about 853.4553893742.

The spelling of 621645044 in words is "six hundred twenty-one million, six hundred forty-five thousand, forty-four".