66716688 has 40 divisors (see below), whose sum is σ = 176024448. Its totient is φ = 21764992.

The previous prime is 66716633. The next prime is 66716707. The reversal of 66716688 is 88661766.

It is a super-4 number, since 4×66716688⁴ (a number of 32 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (48).

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, 12531 + ... + 17042.

Almost surely, 2^66716688 is an apocalyptic number.

It is an amenable number.

66716688 is an abundant number, since it is smaller than the sum of its proper divisors (109307760).

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

66716688 is a wasteful number, since it uses less digits than its factorization.

66716688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29631 (or 29625 counting only the distinct ones).

The product of its digits is 580608, while the sum is 48.

The square root of 66716688 is about 8168.0284034766. The cubic root of 66716688 is about 405.5815209691.

The spelling of 66716688 in words is "sixty-six million, seven hundred sixteen thousand, six hundred eighty-eight".