66917656 has 16 divisors (see below), whose sum is σ = 135122400. Its totient is φ = 30885024.

The previous prime is 66917647. The next prime is 66917659. The reversal of 66917656 is 65671966.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66917659) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 321616 + ... + 321823.

It is an arithmetic number, because the mean of its divisors is an integer number (8445150).

Almost surely, 2^66917656 is an apocalyptic number.

It is an amenable number.

66917656 is an abundant number, since it is smaller than the sum of its proper divisors (68204744).

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

66917656 is a wasteful number, since it uses less digits than its factorization.

66917656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643458 (or 643454 counting only the distinct ones).

The product of its digits is 408240, while the sum is 46.

The square root of 66917656 is about 8180.3212650849. The cubic root of 66917656 is about 405.9883517248.

The spelling of 66917656 in words is "sixty-six million, nine hundred seventeen thousand, six hundred fifty-six".