668694975 has 36 divisors (see below), whose sum is σ = 1197184536. Its totient is φ = 329197440.

The previous prime is 668694973. The next prime is 668694977. The reversal of 668694975 is 579496866.

It is an interprime number because it is at equal distance from previous prime (668694973) and next prime (668694977).

It is not a de Polignac number, because 668694975 - 2¹ = 668694973 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668694973) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 13704 + ... + 39053.

It is an arithmetic number, because the mean of its divisors is an integer number (33255126).

Almost surely, 2^668694975 is an apocalyptic number.

668694975 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

668694975 is a deficient number, since it is larger than the sum of its proper divisors (528489561).

668694975 is a wasteful number, since it uses less digits than its factorization.

668694975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52796 (or 52778 counting only the distinct ones).

The product of its digits is 19595520, while the sum is 60.

The square root of 668694975 is about 25859.1371665800. The cubic root of 668694975 is about 874.4655130350.

The spelling of 668694975 in words is "six hundred sixty-eight million, six hundred ninety-four thousand, nine hundred seventy-five".