66866725 has 12 divisors (see below), whose sum is σ = 83341764. Its totient is φ = 53217920.

The previous prime is 66866717. The next prime is 66866731. The reversal of 66866725 is 52766866.

It can be written as a sum of positive squares in 6 ways, for example, as 14130081 + 52736644 = 3759^2 + 7262^2 .

It is not a de Polignac number, because 66866725 - 2³ = 66866717 is a prime.

It is a Duffinian number.

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, 1864 + ... + 11713.

It is an arithmetic number, because the mean of its divisors is an integer number (6945147).

Almost surely, 2^66866725 is an apocalyptic number.

It is an amenable number.

66866725 is a deficient number, since it is larger than the sum of its proper divisors (16475039).

66866725 is a wasteful number, since it uses less digits than its factorization.

66866725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13784 (or 13779 counting only the distinct ones).

The product of its digits is 725760, while the sum is 46.

The square root of 66866725 is about 8177.2076529828. The cubic root of 66866725 is about 405.8853263946.

The spelling of 66866725 in words is "sixty-six million, eight hundred sixty-six thousand, seven hundred twenty-five".