51165813 has 4 divisors (see below), whose sum is σ = 68221088. Its totient is φ = 34110540.

The previous prime is 51165811. The next prime is 51165817. The reversal of 51165813 is 31856115.

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 not a de Polignac number, because 51165813 - 2¹ = 51165811 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51165811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8527633 + ... + 8527638.

It is an arithmetic number, because the mean of its divisors is an integer number (17055272).

Almost surely, 2^51165813 is an apocalyptic number.

It is an amenable number.

51165813 is a deficient number, since it is larger than the sum of its proper divisors (17055275).

51165813 is a wasteful number, since it uses less digits than its factorization.

51165813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17055274.

The product of its digits is 3600, while the sum is 30.

The square root of 51165813 is about 7153.0282398436. The cubic root of 51165813 is about 371.2444414137.

The spelling of 51165813 in words is "fifty-one million, one hundred sixty-five thousand, eight hundred thirteen".