66387013 has 18 divisors (see below), whose sum is σ = 84892038. Its totient is φ = 51725520.

The previous prime is 66386981. The next prime is 66387031. The reversal of 66387013 is 31078366.

It can be written as a sum of positive squares in only one way, i.e., 49098049 + 17288964 = 7007^2 + 4158^2 .

It is not a de Polignac number, because 66387013 - 2⁵ = 66386981 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66387013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66387073) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 331 + ... + 11527.

Almost surely, 2^66387013 is an apocalyptic number.

It is an amenable number.

66387013 is a deficient number, since it is larger than the sum of its proper divisors (18505025).

66387013 is a wasteful number, since it uses less digits than its factorization.

66387013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11233 (or 11215 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 66387013 is about 8147.8225925704. The cubic root of 66387013 is about 404.9123683795.

The spelling of 66387013 in words is "sixty-six million, three hundred eighty-seven thousand, thirteen".