66888625 has 16 divisors (see below), whose sum is σ = 88390224. Its totient is φ = 50361600.

The previous prime is 66888617. The next prime is 66888629. The reversal of 66888625 is 52688866.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 8946081 + 57942544 = 2991^2 + 7612^2 .

It is not a de Polignac number, because 66888625 - 2³ = 66888617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66888629) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13614 + ... + 17863.

It is an arithmetic number, because the mean of its divisors is an integer number (5524389).

Almost surely, 2^66888625 is an apocalyptic number.

It is an amenable number.

66888625 is a deficient number, since it is larger than the sum of its proper divisors (21501599).

66888625 is a wasteful number, since it uses less digits than its factorization.

66888625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31509 (or 31499 counting only the distinct ones).

The product of its digits is 1105920, while the sum is 49.

The square root of 66888625 is about 8178.5466312787. The cubic root of 66888625 is about 405.9296330280.

The spelling of 66888625 in words is "sixty-six million, eight hundred eighty-eight thousand, six hundred twenty-five".