521115887 has 2 divisors, whose sum is σ = 521115888. Its totient is φ = 521115886.

The previous prime is 521115871. The next prime is 521115893. The reversal of 521115887 is 788511125.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 521115887 - 2⁴ = 521115871 is a prime.

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 521115887.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (521115187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260557943 + 260557944.

It is an arithmetic number, because the mean of its divisors is an integer number (260557944).

Almost surely, 2^521115887 is an apocalyptic number.

521115887 is a deficient number, since it is larger than the sum of its proper divisors (1).

521115887 is an equidigital number, since it uses as much as digits as its factorization.

521115887 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22400, while the sum is 38.

The square root of 521115887 is about 22827.9628307039. The cubic root of 521115887 is about 804.7199555706.

The spelling of 521115887 in words is "five hundred twenty-one million, one hundred fifteen thousand, eight hundred eighty-seven".