51665013 has 16 divisors (see below), whose sum is σ = 77333760. Its totient is φ = 34086528.

The previous prime is 51665011. The next prime is 51665021. The reversal of 51665013 is 31056615.

It is a happy number.

51665013 is a `hidden beast` number, since 5 + 1 + 6 + 650 + 1 + 3 = 666.

It is not a de Polignac number, because 51665013 - 2¹ = 51665011 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51665011) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7245 + ... + 12482.

It is an arithmetic number, because the mean of its divisors is an integer number (4833360).

Almost surely, 2^51665013 is an apocalyptic number.

It is an amenable number.

51665013 is a deficient number, since it is larger than the sum of its proper divisors (25668747).

51665013 is a wasteful number, since it uses less digits than its factorization.

51665013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19833 (or 19827 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 27.

The square root of 51665013 is about 7187.8378529291. The cubic root of 51665013 is about 372.4478866483.

The spelling of 51665013 in words is "fifty-one million, six hundred sixty-five thousand, thirteen".