18520407637 has 2 divisors, whose sum is σ = 18520407638. Its totient is φ = 18520407636.

The previous prime is 18520407611. The next prime is 18520407671. The reversal of 18520407637 is 73670402581.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10413386116 + 8107021521 = 102046^2 + 90039^2 .

It is a cyclic number.

It is not a de Polignac number, because 18520407637 - 2⁷ = 18520407509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18520407593 and 18520407602.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18520497637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9260203818 + 9260203819.

It is an arithmetic number, because the mean of its divisors is an integer number (9260203819).

Almost surely, 2^18520407637 is an apocalyptic number.

It is an amenable number.

18520407637 is a deficient number, since it is larger than the sum of its proper divisors (1).

18520407637 is an equidigital number, since it uses as much as digits as its factorization.

18520407637 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 282240, while the sum is 43.

The spelling of 18520407637 in words is "eighteen billion, five hundred twenty million, four hundred seven thousand, six hundred thirty-seven".