16431045221 has 4 divisors (see below), whose sum is σ = 16431328032. Its totient is φ = 16430762412.

The previous prime is 16431045209. The next prime is 16431045277. The reversal of 16431045221 is 12254013461.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16431045221 - 2²⁶ = 16363936357 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 (16431045821) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18851 + ... + 182256.

It is an arithmetic number, because the mean of its divisors is an integer number (4107832008).

Almost surely, 2^16431045221 is an apocalyptic number.

It is an amenable number.

16431045221 is a deficient number, since it is larger than the sum of its proper divisors (282811).

16431045221 is an equidigital number, since it uses as much as digits as its factorization.

16431045221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 282810.

The product of its (nonzero) digits is 5760, while the sum is 29.

Adding to 16431045221 its reverse (12254013461), we get a palindrome (28685058682).

The spelling of 16431045221 in words is "sixteen billion, four hundred thirty-one million, forty-five thousand, two hundred twenty-one".