66688925 has 12 divisors (see below), whose sum is σ = 83456340. Its totient is φ = 52859520.

The previous prime is 66688903. The next prime is 66688957. The reversal of 66688925 is 52988666.

It can be written as a sum of positive squares in 6 ways, for example, as 851929 + 65836996 = 923^2 + 8114^2 .

It is not a de Polignac number, because 66688925 - 2⁸ = 66688669 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9512 + ... + 14961.

It is an arithmetic number, because the mean of its divisors is an integer number (6954695).

Almost surely, 2^66688925 is an apocalyptic number.

It is an amenable number.

66688925 is a deficient number, since it is larger than the sum of its proper divisors (16767415).

66688925 is a wasteful number, since it uses less digits than its factorization.

66688925 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24592 (or 24587 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 50.

The square root of 66688925 is about 8166.3287345049. The cubic root of 66688925 is about 405.5252545768.

The spelling of 66688925 in words is "sixty-six million, six hundred eighty-eight thousand, nine hundred twenty-five".