211221001992 has 512 divisors, whose sum is σ = 722369249280. Its totient is φ = 49697141760.

The previous prime is 211221001969. The next prime is 211221001993. The reversal of 211221001992 is 299100122112.

211221001992 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×211221001992² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (211221001993) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 326461813 + ... + 326462459.

It is an arithmetic number, because the mean of its divisors is an integer number (1410877440).

Almost surely, 2^211221001992 is an apocalyptic number.

211221001992 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 211221001992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (361184624640).

211221001992 is an abundant number, since it is smaller than the sum of its proper divisors (511148247288).

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

211221001992 is a wasteful number, since it uses less digits than its factorization.

211221001992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 921 (or 917 counting only the distinct ones).

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

The spelling of 211221001992 in words is "two hundred eleven billion, two hundred twenty-one million, one thousand, nine hundred ninety-two".