51656513 has 4 divisors (see below), whose sum is σ = 51679920. Its totient is φ = 51633108.

The previous prime is 51656491. The next prime is 51656519. The reversal of 51656513 is 31565615.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 51656513 - 2¹⁰ = 51655489 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 51656513.

It is not an unprimeable number, because it can be changed into a prime (51656519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8003 + ... + 12936.

It is an arithmetic number, because the mean of its divisors is an integer number (12919980).

Almost surely, 2^51656513 is an apocalyptic number.

It is an amenable number.

51656513 is a deficient number, since it is larger than the sum of its proper divisors (23407).

51656513 is a wasteful number, since it uses less digits than its factorization.

51656513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23406.

The product of its digits is 13500, while the sum is 32.

The square root of 51656513 is about 7187.2465520532. The cubic root of 51656513 is about 372.4274603128.

The spelling of 51656513 in words is "fifty-one million, six hundred fifty-six thousand, five hundred thirteen".