621920 has 72 divisors (see below), whose sum is σ = 1660176. Its totient is φ = 219648.

The previous prime is 621913. The next prime is 621923. The reversal of 621920 is 29126.

621920 = 64² + 65² + ... + 128².

621920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (20).

621920 is a Rhonda number in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 621892 and 621901.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 621920.

It is not an unprimeable number, because it can be changed into a prime (621923) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27029 + ... + 27051.

It is an arithmetic number, because the mean of its divisors is an integer number (23058).

2⁶²¹⁹²⁰ 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 621920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (830088).

621920 is an abundant number, since it is smaller than the sum of its proper divisors (1038256).

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

621920 is a wasteful number, since it uses less digits than its factorization.

621920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64 (or 43 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 621920 is about 788.6190461814. The cubic root of 621920 is about 85.3581199697.

The spelling of 621920 in words is "six hundred twenty-one thousand, nine hundred twenty".