51217811 has 2 divisors, whose sum is σ = 51217812. Its totient is φ = 51217810.

The previous prime is 51217781. The next prime is 51217813. The reversal of 51217811 is 11871215.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 51217811 - 2²² = 47023507 is a prime.

Together with 51217813, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (51217813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25608905 + 25608906.

It is an arithmetic number, because the mean of its divisors is an integer number (25608906).

Almost surely, 2^51217811 is an apocalyptic number.

51217811 is a deficient number, since it is larger than the sum of its proper divisors (1).

51217811 is an equidigital number, since it uses as much as digits as its factorization.

51217811 is an evil number, because the sum of its binary digits is even.

The product of its digits is 560, while the sum is 26.

The square root of 51217811 is about 7156.6620012405. The cubic root of 51217811 is about 371.3701596860.

The spelling of 51217811 in words is "fifty-one million, two hundred seventeen thousand, eight hundred eleven".