87918305261 has 4 divisors (see below), whose sum is σ = 88260400092. Its totient is φ = 87576210432.

The previous prime is 87918305249. The next prime is 87918305291. The reversal of 87918305261 is 16250381978.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 44812656100 + 43105649161 = 211690^2 + 207619^2 .

It is a cyclic number.

It is not a de Polignac number, because 87918305261 - 2²² = 87914110957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87918305201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 171047030 + ... + 171047543.

It is an arithmetic number, because the mean of its divisors is an integer number (22065100023).

Almost surely, 2^87918305261 is an apocalyptic number.

It is an amenable number.

87918305261 is a deficient number, since it is larger than the sum of its proper divisors (342094831).

87918305261 is a wasteful number, since it uses less digits than its factorization.

87918305261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 342094830.

The product of its (nonzero) digits is 725760, while the sum is 50.

The spelling of 87918305261 in words is "eighty-seven billion, nine hundred eighteen million, three hundred five thousand, two hundred sixty-one".