870990581 has 4 divisors (see below), whose sum is σ = 874728972. Its totient is φ = 867252192.

The previous prime is 870990577. The next prime is 870990587. The reversal of 870990581 is 185099078.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 332332900 + 538657681 = 18230^2 + 23209^2 .

It is a cyclic number.

It is not a de Polignac number, because 870990581 - 2² = 870990577 is a prime.

It is a super-2 number, since 2×870990581² = 1517249184381435122, 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 (870990587) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1868846 + ... + 1869311.

It is an arithmetic number, because the mean of its divisors is an integer number (218682243).

Almost surely, 2^870990581 is an apocalyptic number.

It is an amenable number.

870990581 is a deficient number, since it is larger than the sum of its proper divisors (3738391).

870990581 is a wasteful number, since it uses less digits than its factorization.

870990581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3738390.

The product of its (nonzero) digits is 181440, while the sum is 47.

The square root of 870990581 is about 29512.5495509961. The cubic root of 870990581 is about 955.0024509499.

The spelling of 870990581 in words is "eight hundred seventy million, nine hundred ninety thousand, five hundred eighty-one".