621493920 has 144 divisors (see below), whose sum is σ = 2135133000. Its totient is φ = 164616192.

The previous prime is 621493919. The next prime is 621493937. The reversal of 621493920 is 29394126.

621493920 is a `hidden beast` number, since 621 + 4 + 9 + 3 + 9 + 20 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 309900816 + 311593104 = 17604^2 + 17652^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

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 23 ways as a sum of consecutive naturals, for example, 224706 + ... + 227454.

Almost surely, 2^621493920 is an apocalyptic number.

621493920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 621493920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1067566500).

621493920 is an abundant number, since it is smaller than the sum of its proper divisors (1513639080).

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

621493920 is a wasteful number, since it uses less digits than its factorization.

621493920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2927 (or 2916 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 621493920 is about 24929.7797824209. The cubic root of 621493920 is about 853.3862244777.

The spelling of 621493920 in words is "six hundred twenty-one million, four hundred ninety-three thousand, nine hundred twenty".