51238513 has 2 divisors, whose sum is σ = 51238514. Its totient is φ = 51238512.

The previous prime is 51238511. The next prime is 51238519. The reversal of 51238513 is 31583215.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 41049649 + 10188864 = 6407^2 + 3192^2 .

It is a cyclic number.

It is not a de Polignac number, because 51238513 - 2¹ = 51238511 is a prime.

Together with 51238511, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (51238511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25619256 + 25619257.

It is an arithmetic number, because the mean of its divisors is an integer number (25619257).

Almost surely, 2^51238513 is an apocalyptic number.

It is an amenable number.

51238513 is a deficient number, since it is larger than the sum of its proper divisors (1).

51238513 is an equidigital number, since it uses as much as digits as its factorization.

51238513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3600, while the sum is 28.

The square root of 51238513 is about 7158.1081997969. The cubic root of 51238513 is about 371.4201883076.

The spelling of 51238513 in words is "fifty-one million, two hundred thirty-eight thousand, five hundred thirteen".