8861591 has 4 divisors (see below), whose sum is σ = 8943000. Its totient is φ = 8780184.

The previous prime is 8861563. The next prime is 8861597. The reversal of 8861591 is 1951688.

8861591 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 8861591 - 2¹⁰ = 8860567 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 (8861597) 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, 40541 + ... + 40758.

It is an arithmetic number, because the mean of its divisors is an integer number (2235750).

Almost surely, 2^8861591 is an apocalyptic number.

8861591 is a deficient number, since it is larger than the sum of its proper divisors (81409).

8861591 is a wasteful number, since it uses less digits than its factorization.

8861591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81408.

The product of its digits is 17280, while the sum is 38.

The square root of 8861591 is about 2976.8424546825. The cubic root of 8861591 is about 206.9365640682.

Subtracting from 8861591 its reverse (1951688), we obtain a triangular number (6909903 = T₃₇₁₇).

The spelling of 8861591 in words is "eight million, eight hundred sixty-one thousand, five hundred ninety-one".