17894389561 has 4 divisors (see below), whose sum is σ = 17914794532. Its totient is φ = 17873984592.

The previous prime is 17894389559. The next prime is 17894389631. The reversal of 17894389561 is 16598349871.

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 8578279161 + 9316110400 = 92619^2 + 96520^2 .

It is a cyclic number.

It is not a de Polignac number, because 17894389561 - 2¹ = 17894389559 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 17894389561.

It is not an unprimeable number, because it can be changed into a prime (17894309561) 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, 10201170 + ... + 10202923.

It is an arithmetic number, because the mean of its divisors is an integer number (4478698633).

Almost surely, 2^17894389561 is an apocalyptic number.

It is an amenable number.

17894389561 is a deficient number, since it is larger than the sum of its proper divisors (20404971).

17894389561 is an equidigital number, since it uses as much as digits as its factorization.

17894389561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20404970.

The product of its digits is 13063680, while the sum is 61.

The spelling of 17894389561 in words is "seventeen billion, eight hundred ninety-four million, three hundred eighty-nine thousand, five hundred sixty-one".