863812561 has 8 divisors (see below), whose sum is σ = 910681920. Its totient is φ = 817083792.

The previous prime is 863812553. The next prime is 863812601. The reversal of 863812561 is 165218368.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 863812561 - 2³ = 863812553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (863812501) 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 7 ways as a sum of consecutive naturals, for example, 22405 + ... + 47218.

It is an arithmetic number, because the mean of its divisors is an integer number (113835240).

Almost surely, 2^863812561 is an apocalyptic number.

It is an amenable number.

863812561 is a deficient number, since it is larger than the sum of its proper divisors (46869359).

863812561 is a wasteful number, since it uses less digits than its factorization.

863812561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70295.

The product of its digits is 69120, while the sum is 40.

The square root of 863812561 is about 29390.6883383156. The cubic root of 863812561 is about 952.3717509992.

The spelling of 863812561 in words is "eight hundred sixty-three million, eight hundred twelve thousand, five hundred sixty-one".