21621412231216 has 20 divisors (see below), whose sum is σ = 47875984226512. Its totient is φ = 9266319527616.

The previous prime is 21621412231213. The next prime is 21621412231241. The reversal of 21621412231216 is 61213221412612.

It is not an unprimeable number, because it can be changed into a prime (21621412231213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96524161635 + ... + 96524161858.

Almost surely, 2^{21621412231216} is an apocalyptic number.

It is an amenable number.

21621412231216 is an abundant number, since it is smaller than the sum of its proper divisors (26254571995296).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21621412231216 is a wasteful number, since it uses less digits than its factorization.

21621412231216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193048323508 (or 193048323502 counting only the distinct ones).

The product of its digits is 13824, while the sum is 34.

Adding to 21621412231216 its reverse (61213221412612), we get a palindrome (82834633643828).

The spelling of 21621412231216 in words is "twenty-one trillion, six hundred twenty-one billion, four hundred twelve million, two hundred thirty-one thousand, two hundred sixteen".