51391199 has 2 divisors, whose sum is σ = 51391200. Its totient is φ = 51391198.

The previous prime is 51391139. The next prime is 51391201. The reversal of 51391199 is 99119315.

It is a happy number.

51391199 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 51391199 - 2¹² = 51387103 is a prime.

It is a Sophie Germain prime.

Together with 51391201, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51391139) by changing a digit.

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 as a sum of consecutive naturals, namely, 25695599 + 25695600.

It is an arithmetic number, because the mean of its divisors is an integer number (25695600).

Almost surely, 2^51391199 is an apocalyptic number.

51391199 is a deficient number, since it is larger than the sum of its proper divisors (1).

51391199 is an equidigital number, since it uses as much as digits as its factorization.

51391199 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10935, while the sum is 38.

The square root of 51391199 is about 7168.7655143686. The cubic root of 51391199 is about 371.7887549826.

The spelling of 51391199 in words is "fifty-one million, three hundred ninety-one thousand, one hundred ninety-nine".