51249915 has 24 divisors (see below), whose sum is σ = 92125488. Its totient is φ = 27332640.

The previous prime is 51249901. The next prime is 51249923. The reversal of 51249915 is 51994215.

51249915 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 51249915 - 2⁴ = 51249899 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 51249915.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 19876 + ... + 22305.

It is an arithmetic number, because the mean of its divisors is an integer number (3838562).

Almost surely, 2^51249915 is an apocalyptic number.

51249915 is a deficient number, since it is larger than the sum of its proper divisors (40875573).

51249915 is an equidigital number, since it uses as much as digits as its factorization.

51249915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42201 (or 42189 counting only the distinct ones).

The product of its digits is 16200, while the sum is 36.

The square root of 51249915 is about 7158.9045949782. The cubic root of 51249915 is about 371.4477367189.

The spelling of 51249915 in words is "fifty-one million, two hundred forty-nine thousand, nine hundred fifteen".