621725121 has 24 divisors (see below), whose sum is σ = 938223936. Its totient is φ = 395984160.

The previous prime is 621725101. The next prime is 621725149. The reversal of 621725121 is 121527126.

621725121 is a `hidden beast` number, since 621 + 7 + 25 + 12 + 1 = 666.

It is not a de Polignac number, because 621725121 - 2¹⁰ = 621724097 is a prime.

It is not an unprimeable number, because it can be changed into a prime (621725101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 264411 + ... + 266751.

It is an arithmetic number, because the mean of its divisors is an integer number (39092664).

Almost surely, 2^621725121 is an apocalyptic number.

It is an amenable number.

621725121 is a deficient number, since it is larger than the sum of its proper divisors (316498815).

621725121 is a wasteful number, since it uses less digits than its factorization.

621725121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3653 (or 3650 counting only the distinct ones).

The product of its digits is 1680, while the sum is 27.

The square root of 621725121 is about 24934.4163958172. The cubic root of 621725121 is about 853.4920336583.

The spelling of 621725121 in words is "six hundred twenty-one million, seven hundred twenty-five thousand, one hundred twenty-one".