51911491 has 2 divisors, whose sum is σ = 51911492. Its totient is φ = 51911490.

The previous prime is 51911473. The next prime is 51911521. The reversal of 51911491 is 19411915.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51911491 - 2⁵ = 51911459 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (51911471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25955745 + 25955746.

It is an arithmetic number, because the mean of its divisors is an integer number (25955746).

Almost surely, 2^51911491 is an apocalyptic number.

51911491 is a deficient number, since it is larger than the sum of its proper divisors (1).

51911491 is an equidigital number, since it uses as much as digits as its factorization.

51911491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1620, while the sum is 31.

The square root of 51911491 is about 7204.9629423058. The cubic root of 51911491 is about 373.0392256543.

The spelling of 51911491 in words is "fifty-one million, nine hundred eleven thousand, four hundred ninety-one".