870866591 has 4 divisors (see below), whose sum is σ = 995276112. Its totient is φ = 746457072.

The previous prime is 870866551. The next prime is 870866621. The reversal of 870866591 is 195668078.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 195668078 = 2 ⋅97834039.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-870866591 is a prime.

It is a super-2 number, since 2×870866591² = 1516817238639922562, 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 (870866551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 62204750 + ... + 62204763.

It is an arithmetic number, because the mean of its divisors is an integer number (248819028).

Almost surely, 2^870866591 is an apocalyptic number.

870866591 is a deficient number, since it is larger than the sum of its proper divisors (124409521).

870866591 is a wasteful number, since it uses less digits than its factorization.

870866591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124409520.

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

The square root of 870866591 is about 29510.4488444347. The cubic root of 870866591 is about 954.9571322918.

The spelling of 870866591 in words is "eight hundred seventy million, eight hundred sixty-six thousand, five hundred ninety-one".