51815369 has 4 divisors (see below), whose sum is σ = 51855744. Its totient is φ = 51774996.

The previous prime is 51815333. The next prime is 51815377. The reversal of 51815369 is 96351815.

51815369 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 a de Polignac number, because none of the positive numbers 2^k-51815369 is a prime.

It is a super-2 number, since 2×51815369² = 5369664929212322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51815329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18197 + ... + 20850.

It is an arithmetic number, because the mean of its divisors is an integer number (12963936).

Almost surely, 2^51815369 is an apocalyptic number.

It is an amenable number.

51815369 is a deficient number, since it is larger than the sum of its proper divisors (40375).

51815369 is a wasteful number, since it uses less digits than its factorization.

51815369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40374.

The product of its digits is 32400, while the sum is 38.

The square root of 51815369 is about 7198.2893106626. The cubic root of 51815369 is about 372.8088371586.

The spelling of 51815369 in words is "fifty-one million, eight hundred fifteen thousand, three hundred sixty-nine".