87520644257 has 2 divisors, whose sum is σ = 87520644258. Its totient is φ = 87520644256.

The previous prime is 87520644209. The next prime is 87520644307. The reversal of 87520644257 is 75244602578.

It is an a-pointer prime, because the next prime (87520644307) can be obtained adding 87520644257 to its sum of digits (50).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78915484561 + 8605159696 = 280919^2 + 92764^2 .

It is a cyclic number.

It is not a de Polignac number, because 87520644257 - 2⁶ = 87520644193 is a prime.

It is not a weakly prime, because it can be changed into another prime (87520644457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43760322128 + 43760322129.

It is an arithmetic number, because the mean of its divisors is an integer number (43760322129).

Almost surely, 2^87520644257 is an apocalyptic number.

It is an amenable number.

87520644257 is a deficient number, since it is larger than the sum of its proper divisors (1).

87520644257 is an equidigital number, since it uses as much as digits as its factorization.

87520644257 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3763200, while the sum is 50.

The spelling of 87520644257 in words is "eighty-seven billion, five hundred twenty million, six hundred forty-four thousand, two hundred fifty-seven".