668295621 has 48 divisors (see below), whose sum is σ = 1122051840. Its totient is φ = 375425280.

The previous prime is 668295611. The next prime is 668295631. The reversal of 668295621 is 126592866.

668295621 is a `hidden beast` number, since 6 + 6 + 82 + 9 + 562 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (668295611) and next prime (668295631).

It is not a de Polignac number, because 668295621 - 2¹⁰ = 668294597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668295611) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1174225 + ... + 1174793.

It is an arithmetic number, because the mean of its divisors is an integer number (23376080).

Almost surely, 2^668295621 is an apocalyptic number.

It is an amenable number.

668295621 is a deficient number, since it is larger than the sum of its proper divisors (453756219).

668295621 is a wasteful number, since it uses less digits than its factorization.

668295621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 866 (or 863 counting only the distinct ones).

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

The square root of 668295621 is about 25851.4142939995. The cubic root of 668295621 is about 874.2913973537.

The spelling of 668295621 in words is "six hundred sixty-eight million, two hundred ninety-five thousand, six hundred twenty-one".