66557625 has 16 divisors (see below), whose sum is σ = 110752512. Its totient is φ = 35497200.

The previous prime is 66557611. The next prime is 66557633. The reversal of 66557625 is 52675566.

It is a happy number.

It is not a de Polignac number, because 66557625 - 2⁴ = 66557609 is a prime.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 88369 + ... + 89118.

It is an arithmetic number, because the mean of its divisors is an integer number (6922032).

Almost surely, 2^66557625 is an apocalyptic number.

It is an amenable number.

66557625 is a deficient number, since it is larger than the sum of its proper divisors (44194887).

66557625 is a wasteful number, since it uses less digits than its factorization.

66557625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177505 (or 177495 counting only the distinct ones).

The product of its digits is 378000, while the sum is 42.

The square root of 66557625 is about 8158.2856655060. The cubic root of 66557625 is about 405.2589412512.

It can be divided in two parts, 6 and 6557625, that added together give a triangular number (6557631 = T₃₆₂₁).

The spelling of 66557625 in words is "sixty-six million, five hundred fifty-seven thousand, six hundred twenty-five".