51681863 has 2 divisors, whose sum is σ = 51681864. Its totient is φ = 51681862.

The previous prime is 51681841. The next prime is 51681871. The reversal of 51681863 is 36818615.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51681863 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51681893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25840931 + 25840932.

It is an arithmetic number, because the mean of its divisors is an integer number (25840932).

Almost surely, 2^51681863 is an apocalyptic number.

51681863 is a deficient number, since it is larger than the sum of its proper divisors (1).

51681863 is an equidigital number, since it uses as much as digits as its factorization.

51681863 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34560, while the sum is 38.

The square root of 51681863 is about 7189.0098761930. The cubic root of 51681863 is about 372.4883722329.

The spelling of 51681863 in words is "fifty-one million, six hundred eighty-one thousand, eight hundred sixty-three".