66139228 has 12 divisors (see below), whose sum is σ = 121835560. Its totient is φ = 31329072.

The previous prime is 66139211. The next prime is 66139243. The reversal of 66139228 is 82293166.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 435051 + ... + 435202.

Almost surely, 2^66139228 is an apocalyptic number.

It is an amenable number.

66139228 is a deficient number, since it is larger than the sum of its proper divisors (55696332).

66139228 is a wasteful number, since it uses less digits than its factorization.

66139228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 870276 (or 870274 counting only the distinct ones).

The product of its digits is 31104, while the sum is 37.

The square root of 66139228 is about 8132.6027813978. The cubic root of 66139228 is about 404.4079710452.

The spelling of 66139228 in words is "sixty-six million, one hundred thirty-nine thousand, two hundred twenty-eight".