66808511 has 16 divisors (see below), whose sum is σ = 84998400. Its totient is φ = 52055640.

The previous prime is 66808501. The next prime is 66808519. The reversal of 66808511 is 11580866.

It is not a de Polignac number, because 66808511 - 2²² = 62614207 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66808519) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5081 + ... + 12626.

It is an arithmetic number, because the mean of its divisors is an integer number (5312400).

Almost surely, 2^66808511 is an apocalyptic number.

66808511 is a deficient number, since it is larger than the sum of its proper divisors (18189889).

66808511 is a wasteful number, since it uses less digits than its factorization.

66808511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17739 (or 17725 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 66808511 is about 8173.6473498677. The cubic root of 66808511 is about 405.7675046201.

The spelling of 66808511 in words is "sixty-six million, eight hundred eight thousand, five hundred eleven".