66520686 has 16 divisors (see below), whose sum is σ = 134726400. Its totient is φ = 21892728.

The previous prime is 66520673. The next prime is 66520733. The reversal of 66520686 is 68602566.

It is a congruent 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, 69696 + ... + 70643.

It is an arithmetic number, because the mean of its divisors is an integer number (8420400).

Almost surely, 2^66520686 is an apocalyptic number.

66520686 is an abundant number, since it is smaller than the sum of its proper divisors (68205714).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66520686 is a wasteful number, since it uses less digits than its factorization.

66520686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140423.

The product of its (nonzero) digits is 103680, while the sum is 39.

The square root of 66520686 is about 8156.0214565681. The cubic root of 66520686 is about 405.1839554512.

The spelling of 66520686 in words is "sixty-six million, five hundred twenty thousand, six hundred eighty-six".