20305185613 has 4 divisors (see below), whose sum is σ = 20306559040. Its totient is φ = 20303812188.

The previous prime is 20305185599. The next prime is 20305185619. The reversal of 20305185613 is 31658150302.

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.

It is a cyclic number.

It is not a de Polignac number, because 20305185613 - 2⁵ = 20305185581 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 (20305185619) 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, 664293 + ... + 694186.

It is an arithmetic number, because the mean of its divisors is an integer number (5076639760).

Almost surely, 2^20305185613 is an apocalyptic number.

It is an amenable number.

20305185613 is a deficient number, since it is larger than the sum of its proper divisors (1373427).

20305185613 is a wasteful number, since it uses less digits than its factorization.

20305185613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1373426.

The product of its (nonzero) digits is 21600, while the sum is 34.

The spelling of 20305185613 in words is "twenty billion, three hundred five million, one hundred eighty-five thousand, six hundred thirteen".