19965386368 has 16 divisors (see below), whose sum is σ = 39774793410. Its totient is φ = 9982693120.

The previous prime is 19965386303. The next prime is 19965386423. The reversal of 19965386368 is 86368356991.

It can be written as a sum of positive squares in only one way, i.e., 17127480384 + 2837905984 = 130872^2 + 53272^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is a Smith number, since the sum of its digits (64) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (64).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77989663 + ... + 77989918.

Almost surely, 2^19965386368 is an apocalyptic number.

It is an amenable number.

19965386368 is a deficient number, since it is larger than the sum of its proper divisors (19809407042).

19965386368 is an equidigital number, since it uses as much as digits as its factorization.

19965386368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155979595 (or 155979583 counting only the distinct ones).

The product of its digits is 50388480, while the sum is 64.

The spelling of 19965386368 in words is "nineteen billion, nine hundred sixty-five million, three hundred eighty-six thousand, three hundred sixty-eight".