66711915 has 12 divisors (see below), whose sum is σ = 115634064. Its totient is φ = 35579664.

The previous prime is 66711913. The next prime is 66711917. The reversal of 66711915 is 51911766.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66711913) and next prime (66711917).

It is not a de Polignac number, because 66711915 - 2¹ = 66711913 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66711915.

It is not an unprimeable number, because it can be changed into a prime (66711913) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 741199 + ... + 741288.

It is an arithmetic number, because the mean of its divisors is an integer number (9636172).

Almost surely, 2^66711915 is an apocalyptic number.

66711915 is a deficient number, since it is larger than the sum of its proper divisors (48922149).

66711915 is a wasteful number, since it uses less digits than its factorization.

66711915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1482498 (or 1482495 counting only the distinct ones).

The product of its digits is 11340, while the sum is 36.

The square root of 66711915 is about 8167.7362224793. The cubic root of 66711915 is about 405.5718487925.

The spelling of 66711915 in words is "sixty-six million, seven hundred eleven thousand, nine hundred fifteen".