16894993897 has 4 divisors (see below), whose sum is σ = 16895259220. Its totient is φ = 16894728576.

The previous prime is 16894993877. The next prime is 16894993903. The reversal of 16894993897 is 79839949861.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 79839949861 = 7 ⋅11405707123.

It can be written as a sum of positive squares in 2 ways, for example, as 10938858921 + 5956134976 = 104589^2 + 77176^2 .

It is a 3-Lehmer number, since φ(16894993897) divides (16894993897-1)³.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16894993897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16894993837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26533 + ... + 185725.

It is an arithmetic number, because the mean of its divisors is an integer number (4223814805).

It is a Poulet number, since it divides 2^16894993896-1.

Almost surely, 2^16894993897 is an apocalyptic number.

16894993897 is the 106129-th pentagonal number.

It is an amenable number.

16894993897 is a deficient number, since it is larger than the sum of its proper divisors (265323).

16894993897 is a wasteful number, since it uses less digits than its factorization.

16894993897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265322.

The product of its digits is 211631616, while the sum is 73.

The spelling of 16894993897 in words is "sixteen billion, eight hundred ninety-four million, nine hundred ninety-three thousand, eight hundred ninety-seven".