18748786631 has 4 divisors (see below), whose sum is σ = 19255510632. Its totient is φ = 18242062632.

The previous prime is 18748786601. The next prime is 18748786649. The reversal of 18748786631 is 13668784781.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13668784781 = 257 ⋅53185933.

It is a cyclic number.

It is not a de Polignac number, because 18748786631 - 2¹⁴ = 18748770247 is a prime.

It is a super-2 number, since 2×18748786631² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18748786601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 253361945 + ... + 253362018.

It is an arithmetic number, because the mean of its divisors is an integer number (4813877658).

Almost surely, 2^18748786631 is an apocalyptic number.

18748786631 is a deficient number, since it is larger than the sum of its proper divisors (506724001).

18748786631 is an equidigital number, since it uses as much as digits as its factorization.

18748786631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 506724000.

The product of its digits is 10838016, while the sum is 59.

The spelling of 18748786631 in words is "eighteen billion, seven hundred forty-eight million, seven hundred eighty-six thousand, six hundred thirty-one".