87138881 has 8 divisors (see below), whose sum is σ = 94063680. Its totient is φ = 80475472.

The previous prime is 87138871. The next prime is 87138901. The reversal of 87138881 is 18883178.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 87138881 - 2²² = 82944577 is a prime.

It is a super-2 number, since 2×87138881² = 15186369163864322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87138841) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64655 + ... + 65988.

It is an arithmetic number, because the mean of its divisors is an integer number (11757960).

Almost surely, 2^87138881 is an apocalyptic number.

It is an amenable number.

87138881 is a deficient number, since it is larger than the sum of its proper divisors (6924799).

87138881 is a wasteful number, since it uses less digits than its factorization.

87138881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130695.

The product of its digits is 86016, while the sum is 44.

The square root of 87138881 is about 9334.8208874086. The cubic root of 87138881 is about 443.3404177862.

The spelling of 87138881 in words is "eighty-seven million, one hundred thirty-eight thousand, eight hundred eighty-one".