51904513 has 4 divisors (see below), whose sum is σ = 51919060. Its totient is φ = 51889968.

The previous prime is 51904511. The next prime is 51904529. The reversal of 51904513 is 31540915.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 49449024 + 2455489 = 7032^2 + 1567^2 .

It is a cyclic number.

It is not a de Polignac number, because 51904513 - 2¹ = 51904511 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51904511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2143 + ... + 10411.

It is an arithmetic number, because the mean of its divisors is an integer number (12979765).

It is a Proth number, since it is equal to 99 ⋅ 2¹⁹ + 1 and 99 < 2¹⁹.

Almost surely, 2^51904513 is an apocalyptic number.

It is an amenable number.

51904513 is a deficient number, since it is larger than the sum of its proper divisors (14547).

51904513 is an equidigital number, since it uses as much as digits as its factorization.

51904513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14546.

The product of its (nonzero) digits is 2700, while the sum is 28.

The square root of 51904513 is about 7204.4786764901. The cubic root of 51904513 is about 373.0225101237.

The spelling of 51904513 in words is "fifty-one million, nine hundred four thousand, five hundred thirteen".