21621112012 has 12 divisors (see below), whose sum is σ = 37973543440.
Its totient is φ = 10771528176.
The previous prime is 21621112001. The next prime is 21621112039. The reversal of 21621112012 is 21021112612.
Adding to 21621112012 its reverse (21021112612), we get a palindrome (42642224624).
It is an unprimeable number.
It is a pernicious number, because its binary representation contains a prime number (19) of ones.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9755712 + ... + 9757927.
Almost surely, 221621112012 is an apocalyptic number.
It is an amenable number.
21621112012 is a deficient number, since it is larger than the sum of its proper divisors (16352431428).
21621112012 is a wasteful number, since it uses less digits than its factorization.
21621112012 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 19513920 (or 19513918 counting only the distinct ones).
The product of its (nonzero) digits is 96, while the sum is 19.
The spelling of 21621112012 in words is "twenty-one billion, six hundred twenty-one million, one hundred twelve thousand, twelve".