21661031222112 has 96 divisors (see below), whose sum is σ = 60982148747520. Its totient is φ = 6711262871040.

The previous prime is 21661031222069. The next prime is 21661031222191. The reversal of 21661031222112 is 21122213016612.

It is a tau number, because it is divible by the number of its divisors (96).

It is a self number, because there is not a number n which added to its sum of digits gives 21661031222112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 111936964 + ... + 112130307.

It is an arithmetic number, because the mean of its divisors is an integer number (635230716120).

Almost surely, 2^{21661031222112} is an apocalyptic number.

It is an amenable number.

21661031222112 is an abundant number, since it is smaller than the sum of its proper divisors (39321117525408).

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

21661031222112 is a wasteful number, since it uses less digits than its factorization.

21661031222112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224067356 (or 224067348 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 30.

Adding to 21661031222112 its reverse (21122213016612), we get a palindrome (42783244238724).

The spelling of 21661031222112 in words is "twenty-one trillion, six hundred sixty-one billion, thirty-one million, two hundred twenty-two thousand, one hundred twelve".