621919989 has 24 divisors (see below), whose sum is σ = 948380160. Its totient is φ = 391640832.

The previous prime is 621919943. The next prime is 621919999. The reversal of 621919989 is 989919126.

621919989 is a `hidden beast` number, since 621 + 9 + 1 + 9 + 9 + 8 + 9 = 666.

It is not a de Polignac number, because 621919989 - 2⁸ = 621919733 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621919999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 55212 + ... + 65514.

It is an arithmetic number, because the mean of its divisors is an integer number (39515840).

Almost surely, 2^621919989 is an apocalyptic number.

It is an amenable number.

621919989 is a deficient number, since it is larger than the sum of its proper divisors (326460171).

621919989 is a wasteful number, since it uses less digits than its factorization.

621919989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10681 (or 10678 counting only the distinct ones).

The product of its digits is 629856, while the sum is 54.

The square root of 621919989 is about 24938.3237006820. The cubic root of 621919989 is about 853.5811946646.

The spelling of 621919989 in words is "six hundred twenty-one million, nine hundred nineteen thousand, nine hundred eighty-nine".