51321515 has 8 divisors (see below), whose sum is σ = 70383840. Its totient is φ = 35191872.

The previous prime is 51321511. The next prime is 51321539. The reversal of 51321515 is 51512315.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 51321515 - 2² = 51321511 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51321511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 733130 + ... + 733199.

It is an arithmetic number, because the mean of its divisors is an integer number (8797980).

Almost surely, 2^51321515 is an apocalyptic number.

51321515 is a deficient number, since it is larger than the sum of its proper divisors (19062325).

51321515 is a wasteful number, since it uses less digits than its factorization.

51321515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1466341.

The product of its digits is 750, while the sum is 23.

The square root of 51321515 is about 7163.9036146503. The cubic root of 51321515 is about 371.6206364019.

The spelling of 51321515 in words is "fifty-one million, three hundred twenty-one thousand, five hundred fifteen".