667991925 has 54 divisors (see below), whose sum is σ = 1212619746. Its totient is φ = 351499200.

The previous prime is 667991917. The next prime is 667991939. The reversal of 667991925 is 529199766.

It can be written as a sum of positive squares in 3 ways, for example, as 148425489 + 519566436 = 12183^2 + 22794^2 .

It is not a de Polignac number, because 667991925 - 2³ = 667991917 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 3861139 + ... + 3861311.

Almost surely, 2^667991925 is an apocalyptic number.

It is an amenable number.

667991925 is a deficient number, since it is larger than the sum of its proper divisors (544627821).

667991925 is a wasteful number, since it uses less digits than its factorization.

667991925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 451 (or 312 counting only the distinct ones).

The product of its digits is 1837080, while the sum is 54.

The square root of 667991925 is about 25845.5397506030. The cubic root of 667991925 is about 874.1589414853.

The spelling of 667991925 in words is "six hundred sixty-seven million, nine hundred ninety-one thousand, nine hundred twenty-five".