51521812515 has 48 divisors (see below), whose sum is σ = 93278914560. Its totient is φ = 26257746240.

The previous prime is 51521812487. The next prime is 51521812567.

It is a happy number.

51521812515 is a `hidden beast` number, since 5 + 1 + 521 + 8 + 125 + 1 + 5 = 666.

51521812515 is nontrivially palindromic in base 10.

It is a de Polignac number, because none of the positive numbers 2^k-51521812515 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51521812515.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1051410 + ... + 1099320.

It is an arithmetic number, because the mean of its divisors is an integer number (1943310720).

Almost surely, 2^51521812515 is an apocalyptic number.

51521812515 is a deficient number, since it is larger than the sum of its proper divisors (41757102045).

51521812515 is a wasteful number, since it uses less digits than its factorization.

51521812515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48984 (or 48981 counting only the distinct ones).

The product of its digits is 20000, while the sum is 36.

The spelling of 51521812515 in words is "fifty-one billion, five hundred twenty-one million, eight hundred twelve thousand, five hundred fifteen".