51187313 has 2 divisors, whose sum is σ = 51187314. Its totient is φ = 51187312.

The previous prime is 51187309. The next prime is 51187319. The reversal of 51187313 is 31378115.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 51165409 + 21904 = 7153^2 + 148^2 .

It is a cyclic number.

It is not a de Polignac number, because 51187313 - 2² = 51187309 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (51187319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25593656 + 25593657.

It is an arithmetic number, because the mean of its divisors is an integer number (25593657).

Almost surely, 2^51187313 is an apocalyptic number.

It is an amenable number.

51187313 is a deficient number, since it is larger than the sum of its proper divisors (1).

51187313 is an equidigital number, since it uses as much as digits as its factorization.

51187313 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2520, while the sum is 29.

The square root of 51187313 is about 7154.5309419975. The cubic root of 51187313 is about 371.2964334066.

The spelling of 51187313 in words is "fifty-one million, one hundred eighty-seven thousand, three hundred thirteen".