18791783531 has 2 divisors, whose sum is σ = 18791783532. Its totient is φ = 18791783530.

The previous prime is 18791783501. The next prime is 18791783533. The reversal of 18791783531 is 13538719781.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18791783531 - 2³⁰ = 17718041707 is a prime.

It is a super-2 number, since 2×18791783531² (a number of 21 digits) contains 22 as substring.

Together with 18791783533, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18791783533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9395891765 + 9395891766.

It is an arithmetic number, because the mean of its divisors is an integer number (9395891766).

Almost surely, 2^18791783531 is an apocalyptic number.

18791783531 is a deficient number, since it is larger than the sum of its proper divisors (1).

18791783531 is an equidigital number, since it uses as much as digits as its factorization.

18791783531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1270080, while the sum is 53.

The spelling of 18791783531 in words is "eighteen billion, seven hundred ninety-one million, seven hundred eighty-three thousand, five hundred thirty-one".