621680 has 40 divisors (see below), whose sum is σ = 1525200. Its totient is φ = 235008.

The previous prime is 621679. The next prime is 621697. The reversal of 621680 is 86126.

621680 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1316 + ... + 1724.

It is an arithmetic number, because the mean of its divisors is an integer number (38130).

2⁶²¹⁶⁸⁰ 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 621680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (762600).

621680 is an abundant number, since it is smaller than the sum of its proper divisors (903520).

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

621680 is a wasteful number, since it uses less digits than its factorization.

621680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 441 (or 435 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 621680 is about 788.4668667737. The cubic root of 621680 is about 85.3471386085.

The spelling of 621680 in words is "six hundred twenty-one thousand, six hundred eighty".