625668921 has 8 divisors (see below), whose sum is σ = 926916960. Its totient is φ = 417112596.

The previous prime is 625668919. The next prime is 625668947. The reversal of 625668921 is 129866526.

625668921 is a `hidden beast` number, since 6 + 2 + 566 + 89 + 2 + 1 = 666.

It is not a de Polignac number, because 625668921 - 2¹ = 625668919 is a prime.

It is not an unprimeable number, because it can be changed into a prime (625668961) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11586435 + ... + 11586488.

It is an arithmetic number, because the mean of its divisors is an integer number (115864620).

Almost surely, 2^625668921 is an apocalyptic number.

It is an amenable number.

625668921 is a deficient number, since it is larger than the sum of its proper divisors (301248039).

625668921 is a wasteful number, since it uses less digits than its factorization.

625668921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23172932 (or 23172926 counting only the distinct ones).

The product of its digits is 311040, while the sum is 45.

The square root of 625668921 is about 25013.3748422719. The cubic root of 625668921 is about 855.2928882688.

The spelling of 625668921 in words is "six hundred twenty-five million, six hundred sixty-eight thousand, nine hundred twenty-one".