19999999997 has 16 divisors (see below), whose sum is σ = 20560837440. Its totient is φ = 19443739392.

The previous prime is 19999999967. The next prime is 20000000089. The reversal of 19999999997 is 79999999991.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19999999997 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 (19999999967) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16272779 + ... + 16274007.

It is an arithmetic number, because the mean of its divisors is an integer number (1285052340).

Almost surely, 2^19999999997 is an apocalyptic number.

It is an amenable number.

19999999997 is a deficient number, since it is larger than the sum of its proper divisors (560837443).

19999999997 is a wasteful number, since it uses less digits than its factorization.

19999999997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2732.

The product of its digits is 2711943423, while the sum is 89.

The spelling of 19999999997 in words is "nineteen billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred ninety-seven".