621904668 has 108 divisors (see below), whose sum is σ = 1855646856. Its totient is φ = 161515200.

The previous prime is 621904639. The next prime is 621904729. The reversal of 621904668 is 866409126.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 66778 + ... + 75518.

Almost surely, 2^621904668 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 621904668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (927823428).

621904668 is an abundant number, since it is smaller than the sum of its proper divisors (1233742188).

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

621904668 is a wasteful number, since it uses less digits than its factorization.

621904668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8784 (or 8764 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 42.

The square root of 621904668 is about 24938.0165209665. The cubic root of 621904668 is about 853.5741852823.

The spelling of 621904668 in words is "six hundred twenty-one million, nine hundred four thousand, six hundred sixty-eight".