621955840 has 144 divisors (see below), whose sum is σ = 1641217536. Its totient is φ = 223948800.

The previous prime is 621955819. The next prime is 621955847. The reversal of 621955840 is 48559126.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 621955793 and 621955802.

It is not an unprimeable number, because it can be changed into a prime (621955847) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2294905 + ... + 2295175.

It is an arithmetic number, because the mean of its divisors is an integer number (11397344).

Almost surely, 2^621955840 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 621955840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (820608768).

621955840 is an abundant number, since it is smaller than the sum of its proper divisors (1019261696).

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

621955840 is a wasteful number, since it uses less digits than its factorization.

621955840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 466 (or 452 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 40.

The square root of 621955840 is about 24939.0424836239. The cubic root of 621955840 is about 853.5975961053.

The spelling of 621955840 in words is "six hundred twenty-one million, nine hundred fifty-five thousand, eight hundred forty".