621688704 has 128 divisors (see below), whose sum is σ = 2032558080. Its totient is φ = 163952640.

The previous prime is 621688703. The next prime is 621688741. The reversal of 621688704 is 407886126.

It is a tau number, because it is divible by the number of its divisors (128).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621688703) 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, 26049 + ... + 43839.

It is an arithmetic number, because the mean of its divisors is an integer number (15879360).

Almost surely, 2^621688704 is an apocalyptic number.

621688704 is a gapful number since it is divisible by the number (64) 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 621688704, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1016279040).

621688704 is an abundant number, since it is smaller than the sum of its proper divisors (1410869376).

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

621688704 is a wasteful number, since it uses less digits than its factorization.

621688704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17828 (or 17816 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 42.

The square root of 621688704 is about 24933.6861294114. The cubic root of 621688704 is about 853.4753691522.

The spelling of 621688704 in words is "six hundred twenty-one million, six hundred eighty-eight thousand, seven hundred four".