51811967 has 2 divisors, whose sum is σ = 51811968. Its totient is φ = 51811966.

The previous prime is 51811961. The next prime is 51811979. The reversal of 51811967 is 76911815.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51811967 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51811967.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51811961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25905983 + 25905984.

It is an arithmetic number, because the mean of its divisors is an integer number (25905984).

Almost surely, 2^51811967 is an apocalyptic number.

51811967 is a deficient number, since it is larger than the sum of its proper divisors (1).

51811967 is an equidigital number, since it uses as much as digits as its factorization.

51811967 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15120, while the sum is 38.

The square root of 51811967 is about 7198.0530006384. The cubic root of 51811967 is about 372.8006779100.

The spelling of 51811967 in words is "fifty-one million, eight hundred eleven thousand, nine hundred sixty-seven".