87051613921 has 2 divisors, whose sum is σ = 87051613922. Its totient is φ = 87051613920.

The previous prime is 87051613879. The next prime is 87051613927. The reversal of 87051613921 is 12931615078.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 86297287696 + 754326225 = 293764^2 + 27465^2 .

It is a cyclic number.

It is not a de Polignac number, because 87051613921 - 2²⁹ = 86514743009 is a prime.

It is not a weakly prime, because it can be changed into another prime (87051613927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43525806960 + 43525806961.

It is an arithmetic number, because the mean of its divisors is an integer number (43525806961).

Almost surely, 2^87051613921 is an apocalyptic number.

It is an amenable number.

87051613921 is a deficient number, since it is larger than the sum of its proper divisors (1).

87051613921 is an equidigital number, since it uses as much as digits as its factorization.

87051613921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90720, while the sum is 43.

The spelling of 87051613921 in words is "eighty-seven billion, fifty-one million, six hundred thirteen thousand, nine hundred twenty-one".