66979887 has 32 divisors (see below), whose sum is σ = 101606400. Its totient is φ = 38936832.

The previous prime is 66979877. The next prime is 66979897. The reversal of 66979887 is 78897966.

It is an interprime number because it is at equal distance from previous prime (66979877) and next prime (66979897).

It is not a de Polignac number, because 66979887 - 2⁶ = 66979823 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66979887.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66979877) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 79414 + ... + 80252.

It is an arithmetic number, because the mean of its divisors is an integer number (3175200).

Almost surely, 2^66979887 is an apocalyptic number.

66979887 is a deficient number, since it is larger than the sum of its proper divisors (34626513).

66979887 is a wasteful number, since it uses less digits than its factorization.

66979887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 967.

The product of its digits is 9144576, while the sum is 60.

The square root of 66979887 is about 8184.1240826371. The cubic root of 66979887 is about 406.1141642274.

The spelling of 66979887 in words is "sixty-six million, nine hundred seventy-nine thousand, eight hundred eighty-seven".