51387251 has 2 divisors, whose sum is σ = 51387252. Its totient is φ = 51387250.

The previous prime is 51387247. The next prime is 51387257. The reversal of 51387251 is 15278315.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51387251 - 2² = 51387247 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (51387257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25693625 + 25693626.

It is an arithmetic number, because the mean of its divisors is an integer number (25693626).

Almost surely, 2^51387251 is an apocalyptic number.

51387251 is a deficient number, since it is larger than the sum of its proper divisors (1).

51387251 is an equidigital number, since it uses as much as digits as its factorization.

51387251 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8400, while the sum is 32.

The square root of 51387251 is about 7168.4901478624. The cubic root of 51387251 is about 371.7792341592.

The spelling of 51387251 in words is "fifty-one million, three hundred eighty-seven thousand, two hundred fifty-one".