19935645813 has 12 divisors (see below), whose sum is σ = 29160439360. Its totient is φ = 13122196776.

The previous prime is 19935645809. The next prime is 19935645911. The reversal of 19935645813 is 31854653991.

19935645813 is a `hidden beast` number, since 1 + 9 + 9 + 3 + 56 + 4 + 581 + 3 = 666.

It is not a de Polignac number, because 19935645813 - 2² = 19935645809 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19935645813.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19935645113) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14018731 + ... + 14020152.

Almost surely, 2^19935645813 is an apocalyptic number.

It is an amenable number.

19935645813 is a deficient number, since it is larger than the sum of its proper divisors (9224793547).

19935645813 is a wasteful number, since it uses less digits than its factorization.

19935645813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28038968 (or 28038965 counting only the distinct ones).

The product of its digits is 3499200, while the sum is 54.

The spelling of 19935645813 in words is "nineteen billion, nine hundred thirty-five million, six hundred forty-five thousand, eight hundred thirteen".