87705589521 has 16 divisors (see below), whose sum is σ = 134286071040. Its totient is φ = 50357275920.

The previous prime is 87705589513. The next prime is 87705589537. The reversal of 87705589521 is 12598550778.

It is not a de Polignac number, because 87705589521 - 2³ = 87705589513 is a prime.

It is a super-2 number, since 2×87705589521² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (87705589501) 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 in 15 ways as a sum of consecutive naturals, for example, 69940035 + ... + 69941288.

It is an arithmetic number, because the mean of its divisors is an integer number (8392879440).

Almost surely, 2^87705589521 is an apocalyptic number.

It is an amenable number.

87705589521 is a deficient number, since it is larger than the sum of its proper divisors (46580481519).

87705589521 is a wasteful number, since it uses less digits than its factorization.

87705589521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139881356.

The product of its (nonzero) digits is 7056000, while the sum is 57.

The spelling of 87705589521 in words is "eighty-seven billion, seven hundred five million, five hundred eighty-nine thousand, five hundred twenty-one".