87137791 has 4 divisors (see below), whose sum is σ = 93840712. Its totient is φ = 80434872.

The previous prime is 87137789. The next prime is 87137797. The reversal of 87137791 is 19773178.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19773178 = 2 ⋅9886589.

It is a cyclic number.

It is not a de Polignac number, because 87137791 - 2¹ = 87137789 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 (87137797) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3351441 + ... + 3351466.

It is an arithmetic number, because the mean of its divisors is an integer number (23460178).

Almost surely, 2^87137791 is an apocalyptic number.

87137791 is a deficient number, since it is larger than the sum of its proper divisors (6702921).

87137791 is a wasteful number, since it uses less digits than its factorization.

87137791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6702920.

The product of its digits is 74088, while the sum is 43.

The square root of 87137791 is about 9334.7625036741. The cubic root of 87137791 is about 443.3385692311.

The spelling of 87137791 in words is "eighty-seven million, one hundred thirty-seven thousand, seven hundred ninety-one".