51506519 has 4 divisors (see below), whose sum is σ = 51834744. Its totient is φ = 51178296.

The previous prime is 51506503. The next prime is 51506569. The reversal of 51506519 is 91560515.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 51506519 - 2⁴ = 51506503 is a prime.

It is a super-2 number, since 2×51506519² = 5305842998994722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51506569) 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, 163877 + ... + 164190.

It is an arithmetic number, because the mean of its divisors is an integer number (12958686).

Almost surely, 2^51506519 is an apocalyptic number.

51506519 is a deficient number, since it is larger than the sum of its proper divisors (328225).

51506519 is a wasteful number, since it uses less digits than its factorization.

51506519 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328224.

The product of its (nonzero) digits is 6750, while the sum is 32.

The square root of 51506519 is about 7176.8042330831. The cubic root of 51506519 is about 372.0666407570.

It can be divided in two parts, 51506 and 519, that added together give a palindrome (52025).

The spelling of 51506519 in words is "fifty-one million, five hundred six thousand, five hundred nineteen".