19866894293 has 4 divisors (see below), whose sum is σ = 20403837420. Its totient is φ = 19329951168.

The previous prime is 19866894241. The next prime is 19866894349. The reversal of 19866894293 is 39249866891.

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 10438095889 + 9428798404 = 102167^2 + 97102^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19866894293 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19866890293) 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, 268471508 + ... + 268471581.

It is an arithmetic number, because the mean of its divisors is an integer number (5100959355).

Almost surely, 2^19866894293 is an apocalyptic number.

It is an amenable number.

19866894293 is a deficient number, since it is larger than the sum of its proper divisors (536943127).

19866894293 is an equidigital number, since it uses as much as digits as its factorization.

19866894293 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 536943126.

The product of its digits is 40310784, while the sum is 65.

The spelling of 19866894293 in words is "nineteen billion, eight hundred sixty-six million, eight hundred ninety-four thousand, two hundred ninety-three".