16721840667399 has 32 divisors (see below), whose sum is σ = 25914369761280. Its totient is φ = 9392806264800.

The previous prime is 16721840667379. The next prime is 16721840667409. The reversal of 16721840667399 is 99376604812761.

It is not a de Polignac number, because 16721840667399 - 2²¹ = 16721838570247 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16721840667359) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20200054 + ... + 21011564.

It is an arithmetic number, because the mean of its divisors is an integer number (809824055040).

Almost surely, 2^{16721840667399} is an apocalyptic number.

16721840667399 is a deficient number, since it is larger than the sum of its proper divisors (9192529093881).

16721840667399 is a wasteful number, since it uses less digits than its factorization.

16721840667399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 828211.

The product of its (nonzero) digits is 164602368, while the sum is 69.

The spelling of 16721840667399 in words is "sixteen trillion, seven hundred twenty-one billion, eight hundred forty million, six hundred sixty-seven thousand, three hundred ninety-nine".