66506139 has 24 divisors (see below), whose sum is σ = 111299552. Its totient is φ = 37480320.

The previous prime is 66506117. The next prime is 66506147. The reversal of 66506139 is 93160566.

It is not a de Polignac number, because 66506139 - 2⁵ = 66506107 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (66506189) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2632 + ... + 11829.

Almost surely, 2^66506139 is an apocalyptic number.

66506139 is a deficient number, since it is larger than the sum of its proper divisors (44793413).

66506139 is a wasteful number, since it uses less digits than its factorization.

66506139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14547 (or 14544 counting only the distinct ones).

The product of its (nonzero) digits is 29160, while the sum is 36.

The square root of 66506139 is about 8155.1296127039. The cubic root of 66506139 is about 405.1544175683.

The spelling of 66506139 in words is "sixty-six million, five hundred six thousand, one hundred thirty-nine".