66888890 has 16 divisors (see below), whose sum is σ = 122441760. Its totient is φ = 26301840.

The previous prime is 66888889. The next prime is 66888907. The reversal of 66888890 is 9888866.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56096 + ... + 57275.

It is an arithmetic number, because the mean of its divisors is an integer number (7652610).

Almost surely, 2^66888890 is an apocalyptic number.

66888890 is a deficient number, since it is larger than the sum of its proper divisors (55552870).

66888890 is a wasteful number, since it uses less digits than its factorization.

66888890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113437.

The product of its (nonzero) digits is 1327104, while the sum is 53.

The square root of 66888890 is about 8178.5628321851. The cubic root of 66888890 is about 405.9301690993.

The spelling of 66888890 in words is "sixty-six million, eight hundred eighty-eight thousand, eight hundred ninety".