669999975 has 24 divisors (see below), whose sum is σ = 1111311312. Its totient is φ = 356179200.

The previous prime is 669999961. The next prime is 669999989. The reversal of 669999975 is 579999966.

It is an interprime number because it is at equal distance from previous prime (669999961) and next prime (669999989).

It is not a de Polignac number, because 669999975 - 2⁸ = 669999719 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9205 + ... + 37745.

It is an arithmetic number, because the mean of its divisors is an integer number (46304638).

Almost surely, 2^669999975 is an apocalyptic number.

669999975 is a deficient number, since it is larger than the sum of its proper divisors (441311337).

669999975 is a wasteful number, since it uses less digits than its factorization.

669999975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28867 (or 28862 counting only the distinct ones).

The product of its digits is 74401740, while the sum is 69.

The square root of 669999975 is about 25884.3577281724. The cubic root of 669999975 is about 875.0340013998.

Subtracting from 669999975 its reverse (579999966), we obtain a palindrome (90000009).

The spelling of 669999975 in words is "six hundred sixty-nine million, nine hundred ninety-nine thousand, nine hundred seventy-five".