16213363621721 has 32 divisors (see below), whose sum is σ = 19977075993600. Its totient is φ = 12847524540480.

The previous prime is 16213363621709. The next prime is 16213363621747. The reversal of 16213363621721 is 12712636331261.

It is not a de Polignac number, because 16213363621721 - 2²⁶ = 16213296512857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16213363621781) 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, 4787606 + ... + 7439616.

It is an arithmetic number, because the mean of its divisors is an integer number (624283624800).

Almost surely, 2^{16213363621721} is an apocalyptic number.

It is an amenable number.

16213363621721 is a deficient number, since it is larger than the sum of its proper divisors (3763712371879).

16213363621721 is a wasteful number, since it uses less digits than its factorization.

16213363621721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2653149.

The product of its digits is 326592, while the sum is 44.

Adding to 16213363621721 its reverse (12712636331261), we get a palindrome (28925999952982).

The spelling of 16213363621721 in words is "sixteen trillion, two hundred thirteen billion, three hundred sixty-three million, six hundred twenty-one thousand, seven hundred twenty-one".