21121200001992 has 128 divisors (see below), whose sum is σ = 57509331840000. Its totient is φ = 6438670269696.

The previous prime is 21121200001987. The next prime is 21121200002009. The reversal of 21121200001992 is 29910000212112.

It is a super-2 number, since 2×21121200001992² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 72944559 + ... + 73233537.

It is an arithmetic number, because the mean of its divisors is an integer number (449291655000).

Almost surely, 2^{21121200001992} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21121200001992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28754665920000).

21121200001992 is an abundant number, since it is smaller than the sum of its proper divisors (36388131838008).

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

21121200001992 is a wasteful number, since it uses less digits than its factorization.

21121200001992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 294563 (or 294559 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 30.

The spelling of 21121200001992 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred million, one thousand, nine hundred ninety-two".