51239911 has 2 divisors, whose sum is σ = 51239912. Its totient is φ = 51239910.

The previous prime is 51239863. The next prime is 51239957. The reversal of 51239911 is 11993215.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 51239911 - 2⁹ = 51239399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51239971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25619955 + 25619956.

It is an arithmetic number, because the mean of its divisors is an integer number (25619956).

Almost surely, 2^51239911 is an apocalyptic number.

51239911 is a deficient number, since it is larger than the sum of its proper divisors (1).

51239911 is an equidigital number, since it uses as much as digits as its factorization.

51239911 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2430, while the sum is 31.

The square root of 51239911 is about 7158.2058506304. The cubic root of 51239911 is about 371.4235662400.

The spelling of 51239911 in words is "fifty-one million, two hundred thirty-nine thousand, nine hundred eleven".