620791921 has 4 divisors (see below), whose sum is σ = 653465200. Its totient is φ = 588118644.

The previous prime is 620791909. The next prime is 620791967. The reversal of 620791921 is 129197026.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 620791921 - 2⁵ = 620791889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (620791991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16336611 + ... + 16336648.

It is an arithmetic number, because the mean of its divisors is an integer number (163366300).

Almost surely, 2^620791921 is an apocalyptic number.

It is an amenable number.

620791921 is a deficient number, since it is larger than the sum of its proper divisors (32673279).

620791921 is a wasteful number, since it uses less digits than its factorization.

620791921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32673278.

The product of its (nonzero) digits is 13608, while the sum is 37.

The square root of 620791921 is about 24915.6962776480. The cubic root of 620791921 is about 853.0647936169.

It can be divided in two parts, 62079 and 1921, that added together give a cube (64000 = 40³).

The spelling of 620791921 in words is "six hundred twenty million, seven hundred ninety-one thousand, nine hundred twenty-one".