51515779 has 4 divisors (see below), whose sum is σ = 58875184. Its totient is φ = 44156376.

The previous prime is 51515773. The next prime is 51515801. The reversal of 51515779 is 97751515.

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 51515779 - 2³ = 51515771 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51515771) 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, 3679692 + ... + 3679705.

It is an arithmetic number, because the mean of its divisors is an integer number (14718796).

Almost surely, 2^51515779 is an apocalyptic number.

51515779 is a deficient number, since it is larger than the sum of its proper divisors (7359405).

51515779 is an equidigital number, since it uses as much as digits as its factorization.

51515779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7359404.

The product of its digits is 55125, while the sum is 40.

The square root of 51515779 is about 7177.4493380309. The cubic root of 51515779 is about 372.0889365150.

The spelling of 51515779 in words is "fifty-one million, five hundred fifteen thousand, seven hundred seventy-nine".