18785979589 has 4 divisors (see below), whose sum is σ = 20231054956. Its totient is φ = 17340904224.

The previous prime is 18785979581. The next prime is 18785979593. The reversal of 18785979589 is 98597958781.

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 5540271489 + 13245708100 = 74433^2 + 115090^2 .

It is a cyclic number.

It is not a de Polignac number, because 18785979589 - 2³ = 18785979581 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18785979581) 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, 722537664 + ... + 722537689.

It is an arithmetic number, because the mean of its divisors is an integer number (5057763739).

Almost surely, 2^18785979589 is an apocalyptic number.

It is an amenable number.

18785979589 is a deficient number, since it is larger than the sum of its proper divisors (1445075367).

18785979589 is a wasteful number, since it uses less digits than its factorization.

18785979589 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1445075366.

The product of its digits is 457228800, while the sum is 76.

The spelling of 18785979589 in words is "eighteen billion, seven hundred eighty-five million, nine hundred seventy-nine thousand, five hundred eighty-nine".