51861287 has 2 divisors, whose sum is σ = 51861288. Its totient is φ = 51861286.

The previous prime is 51861281. The next prime is 51861289. The reversal of 51861287 is 78216815.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51861287 is a prime.

Together with 51861289, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51861287.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51861281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25930643 + 25930644.

It is an arithmetic number, because the mean of its divisors is an integer number (25930644).

Almost surely, 2^51861287 is an apocalyptic number.

51861287 is a deficient number, since it is larger than the sum of its proper divisors (1).

51861287 is an equidigital number, since it uses as much as digits as its factorization.

51861287 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 26880, while the sum is 38.

The square root of 51861287 is about 7201.4781121656. The cubic root of 51861287 is about 372.9189305038.

The spelling of 51861287 in words is "fifty-one million, eight hundred sixty-one thousand, two hundred eighty-seven".