51866387 has 2 divisors, whose sum is σ = 51866388. Its totient is φ = 51866386.

The previous prime is 51866377. The next prime is 51866393. The reversal of 51866387 is 78366815.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51866387 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (51866327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25933193 + 25933194.

It is an arithmetic number, because the mean of its divisors is an integer number (25933194).

Almost surely, 2^51866387 is an apocalyptic number.

51866387 is a deficient number, since it is larger than the sum of its proper divisors (1).

51866387 is an equidigital number, since it uses as much as digits as its factorization.

51866387 is an evil number, because the sum of its binary digits is even.

The product of its digits is 241920, while the sum is 44.

The square root of 51866387 is about 7201.8321974342. The cubic root of 51866387 is about 372.9311542922.

The spelling of 51866387 in words is "fifty-one million, eight hundred sixty-six thousand, three hundred eighty-seven".