87235991 has 4 divisors (see below), whose sum is σ = 87290112. Its totient is φ = 87181872.

The previous prime is 87235969. The next prime is 87236021. The reversal of 87235991 is 19953278.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19953278 = 2 ⋅9976639.

It is a cyclic number.

It is not a de Polignac number, because 87235991 - 2⁶ = 87235927 is a prime.

It is a super-2 number, since 2×87235991² = 15220236251504162, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87235921) 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, 24566 + ... + 27891.

It is an arithmetic number, because the mean of its divisors is an integer number (21822528).

Almost surely, 2^87235991 is an apocalyptic number.

87235991 is a deficient number, since it is larger than the sum of its proper divisors (54121).

87235991 is a wasteful number, since it uses less digits than its factorization.

87235991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54120.

The product of its digits is 136080, while the sum is 44.

The square root of 87235991 is about 9340.0209314541. The cubic root of 87235991 is about 443.5050469555.

It can be divided in two parts, 872 and 35991, that added together give a palindrome (36863).

The spelling of 87235991 in words is "eighty-seven million, two hundred thirty-five thousand, nine hundred ninety-one".