19953688965 has 64 divisors (see below), whose sum is σ = 37109193216. Its totient is φ = 8966909952.

The previous prime is 19953688961. The next prime is 19953688969. The reversal of 19953688965 is 56988635991.

It is an interprime number because it is at equal distance from previous prime (19953688961) and next prime (19953688969).

It is not a de Polignac number, because 19953688965 - 2² = 19953688961 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19953688965.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19953688961) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2394987 + ... + 2403303.

It is an arithmetic number, because the mean of its divisors is an integer number (579831144).

Almost surely, 2^19953688965 is an apocalyptic number.

19953688965 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19953688965 is a deficient number, since it is larger than the sum of its proper divisors (17155504251).

19953688965 is a wasteful number, since it uses less digits than its factorization.

19953688965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8718.

The product of its digits is 125971200, while the sum is 69.

The spelling of 19953688965 in words is "nineteen billion, nine hundred fifty-three million, six hundred eighty-eight thousand, nine hundred sixty-five".