18520407613 has 4 divisors (see below), whose sum is σ = 18520888320. Its totient is φ = 18519926908.

The previous prime is 18520407611. The next prime is 18520407637. The reversal of 18520407613 is 31670402581.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 31670402581 = 503 ⋅62963027.

It is a cyclic number.

It is not a de Polignac number, because 18520407613 - 2¹ = 18520407611 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 (18520407611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 176995 + ... + 261472.

It is an arithmetic number, because the mean of its divisors is an integer number (4630222080).

Almost surely, 2^18520407613 is an apocalyptic number.

It is an amenable number.

18520407613 is a deficient number, since it is larger than the sum of its proper divisors (480707).

18520407613 is an equidigital number, since it uses as much as digits as its factorization.

18520407613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 480706.

The product of its (nonzero) digits is 40320, while the sum is 37.

The spelling of 18520407613 in words is "eighteen billion, five hundred twenty million, four hundred seven thousand, six hundred thirteen".