16431232512221 has 16 divisors (see below), whose sum is σ = 16488132837120. Its totient is φ = 16374419043840.

The previous prime is 16431232512169. The next prime is 16431232512239. The reversal of 16431232512221 is 12221523213461.

It is a cyclic number.

It is not a de Polignac number, because 16431232512221 - 2⁶ = 16431232512157 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 (16431232502221) 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, 2913852920 + ... + 2913858558.

It is an arithmetic number, because the mean of its divisors is an integer number (1030508302320).

Almost surely, 2^{16431232512221} is an apocalyptic number.

It is an amenable number.

16431232512221 is a deficient number, since it is larger than the sum of its proper divisors (56900324899).

16431232512221 is a wasteful number, since it uses less digits than its factorization.

16431232512221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11644.

The product of its digits is 34560, while the sum is 35.

Adding to 16431232512221 its reverse (12221523213461), we get a palindrome (28652755725682).

The spelling of 16431232512221 in words is "sixteen trillion, four hundred thirty-one billion, two hundred thirty-two million, five hundred twelve thousand, two hundred twenty-one".