66912807 has 8 divisors (see below), whose sum is σ = 96079984. Its totient is φ = 41177088.

The previous prime is 66912757. The next prime is 66912821. The reversal of 66912807 is 70821966.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66912807 - 2⁷ = 66912679 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39), and also a Moran number because the ratio is a prime number: 1715713 = 66912807 / (6 + 6 + 9 + 1 + 2 + 8 + 0 + 7).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66912847) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 857818 + ... + 857895.

It is an arithmetic number, because the mean of its divisors is an integer number (12009998).

Almost surely, 2^66912807 is an apocalyptic number.

66912807 is a deficient number, since it is larger than the sum of its proper divisors (29167177).

66912807 is a wasteful number, since it uses less digits than its factorization.

66912807 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1715729.

The product of its (nonzero) digits is 36288, while the sum is 39.

The square root of 66912807 is about 8180.0248777128. The cubic root of 66912807 is about 405.9785452194.

The spelling of 66912807 in words is "sixty-six million, nine hundred twelve thousand, eight hundred seven".