87866591 has 4 divisors (see below), whose sum is σ = 93035232. Its totient is φ = 82697952.

The previous prime is 87866573. The next prime is 87866609. The reversal of 87866591 is 19566878.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (87866573) and next prime (87866609).

It is a cyclic number.

It is not a de Polignac number, because 87866591 - 2²² = 83672287 is a prime.

It is a super-2 number, since 2×87866591² = 15441075627922562, 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 (87866521) 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, 2584295 + ... + 2584328.

It is an arithmetic number, because the mean of its divisors is an integer number (23258808).

Almost surely, 2^87866591 is an apocalyptic number.

87866591 is a deficient number, since it is larger than the sum of its proper divisors (5168641).

87866591 is a wasteful number, since it uses less digits than its factorization.

87866591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5168640.

The product of its digits is 725760, while the sum is 50.

The square root of 87866591 is about 9373.7180990256. The cubic root of 87866591 is about 444.5711324932.

The spelling of 87866591 in words is "eighty-seven million, eight hundred sixty-six thousand, five hundred ninety-one".