51321287 has 2 divisors, whose sum is σ = 51321288. Its totient is φ = 51321286.

The previous prime is 51321253. The next prime is 51321289. The reversal of 51321287 is 78212315.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 51321287 - 2²⁰ = 50272711 is a prime.

Together with 51321289, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_3075536 and since 51321287 and 3075536 have the same sum of digits, it is a Honaker prime.

It is a zygodrome in base 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51321289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25660643 + 25660644.

It is an arithmetic number, because the mean of its divisors is an integer number (25660644).

Almost surely, 2^51321287 is an apocalyptic number.

51321287 is a deficient number, since it is larger than the sum of its proper divisors (1).

51321287 is an equidigital number, since it uses as much as digits as its factorization.

51321287 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3360, while the sum is 29.

The square root of 51321287 is about 7163.8877015207. The cubic root of 51321287 is about 371.6200860828.

The spelling of 51321287 in words is "fifty-one million, three hundred twenty-one thousand, two hundred eighty-seven".