18782087431 has 4 divisors (see below), whose sum is σ = 19598699952. Its totient is φ = 17965474912.

The previous prime is 18782087417. The next prime is 18782087479. The reversal of 18782087431 is 13478028781.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18782087431 - 2⁹ = 18782086919 is a prime.

It is a super-2 number, since 2×18782087431² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18782087411) 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, 408306226 + ... + 408306271.

It is an arithmetic number, because the mean of its divisors is an integer number (4899674988).

Almost surely, 2^18782087431 is an apocalyptic number.

18782087431 is a deficient number, since it is larger than the sum of its proper divisors (816612521).

18782087431 is an equidigital number, since it uses as much as digits as its factorization.

18782087431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 816612520.

The product of its (nonzero) digits is 602112, while the sum is 49.

The spelling of 18782087431 in words is "eighteen billion, seven hundred eighty-two million, eighty-seven thousand, four hundred thirty-one".