18715031893 has 4 divisors (see below), whose sum is σ = 19815916140. Its totient is φ = 17614147648.

The previous prime is 18715031887. The next prime is 18715031957. The reversal of 18715031893 is 39813051781.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 39813051781 = 106109 ⋅375209.

It can be written as a sum of positive squares in 2 ways, for example, as 4962075364 + 13752956529 = 70442^2 + 117273^2 .

It is a cyclic number.

It is not a de Polignac number, because 18715031893 - 2⁹ = 18715031381 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 (18715031833) 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, 550442098 + ... + 550442131.

It is an arithmetic number, because the mean of its divisors is an integer number (4953979035).

Almost surely, 2^18715031893 is an apocalyptic number.

It is an amenable number.

18715031893 is a deficient number, since it is larger than the sum of its proper divisors (1100884247).

18715031893 is a wasteful number, since it uses less digits than its factorization.

18715031893 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1100884246.

The product of its (nonzero) digits is 181440, while the sum is 46.

The spelling of 18715031893 in words is "eighteen billion, seven hundred fifteen million, thirty-one thousand, eight hundred ninety-three".