864993561 has 8 divisors (see below), whose sum is σ = 1155895200. Its totient is φ = 575377152.

The previous prime is 864993559. The next prime is 864993583. The reversal of 864993561 is 165399468.

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

It is not a de Polignac number, because 864993561 - 2¹ = 864993559 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (864997561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 319735 + ... + 322428.

It is an arithmetic number, because the mean of its divisors is an integer number (144486900).

Almost surely, 2^864993561 is an apocalyptic number.

It is an amenable number.

864993561 is a deficient number, since it is larger than the sum of its proper divisors (290901639).

864993561 is a wasteful number, since it uses less digits than its factorization.

864993561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 642615.

The product of its digits is 1399680, while the sum is 51.

The square root of 864993561 is about 29410.7728732177. The cubic root of 864993561 is about 952.8055792366.

The spelling of 864993561 in words is "eight hundred sixty-four million, nine hundred ninety-three thousand, five hundred sixty-one".