87138291 has 4 divisors (see below), whose sum is σ = 116184392. Its totient is φ = 58092192.

The previous prime is 87138269. The next prime is 87138299. The reversal of 87138291 is 19283178.

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

It is a de Polignac number, because none of the positive numbers 2^k-87138291 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87138299) 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 3 ways as a sum of consecutive naturals, for example, 14523046 + ... + 14523051.

It is an arithmetic number, because the mean of its divisors is an integer number (29046098).

Almost surely, 2^87138291 is an apocalyptic number.

87138291 is a deficient number, since it is larger than the sum of its proper divisors (29046101).

87138291 is a wasteful number, since it uses less digits than its factorization.

87138291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29046100.

The product of its digits is 24192, while the sum is 39.

The square root of 87138291 is about 9334.7892852490. The cubic root of 87138291 is about 443.3394171940.

The spelling of 87138291 in words is "eighty-seven million, one hundred thirty-eight thousand, two hundred ninety-one".