66389888 has 32 divisors (see below), whose sum is σ = 132651000. Its totient is φ = 33097216.

The previous prime is 66389887. The next prime is 66389909. The reversal of 66389888 is 88898366.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66389887) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64643 + ... + 65661.

Almost surely, 2^66389888 is an apocalyptic number.

It is an amenable number.

66389888 is a deficient number, since it is larger than the sum of its proper divisors (66261112).

66389888 is a wasteful number, since it uses less digits than its factorization.

66389888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1542 (or 1530 counting only the distinct ones).

The product of its digits is 3981312, while the sum is 56.

The square root of 66389888 is about 8147.9990181639. Note that the first 3 decimals coincide. The cubic root of 66389888 is about 404.9182134296.

The spelling of 66389888 in words is "sixty-six million, three hundred eighty-nine thousand, eight hundred eighty-eight".