87181139 has 24 divisors (see below), whose sum is σ = 96944688. Its totient is φ = 78304320.

The previous prime is 87181111. The next prime is 87181153. The reversal of 87181139 is 93118178.

It is a de Polignac number, because none of the positive numbers 2^k-87181139 is a prime.

Its product of digits (12096) is a multiple of the sum of its prime divisors (224).

It is not an unprimeable number, because it can be changed into a prime (87181189) 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 in 23 ways as a sum of consecutive naturals, for example, 814724 + ... + 814830.

It is an arithmetic number, because the mean of its divisors is an integer number (4039362).

Almost surely, 2^87181139 is an apocalyptic number.

87181139 is a deficient number, since it is larger than the sum of its proper divisors (9763549).

87181139 is a wasteful number, since it uses less digits than its factorization.

87181139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243 (or 224 counting only the distinct ones).

The product of its digits is 12096, while the sum is 38.

The square root of 87181139 is about 9337.0840737352. The cubic root of 87181139 is about 443.4120721824.

The spelling of 87181139 in words is "eighty-seven million, one hundred eighty-one thousand, one hundred thirty-nine".