211221980 has 12 divisors (see below), whose sum is σ = 443566200. Its totient is φ = 84488784.

The previous prime is 211221979. The next prime is 211222019. The reversal of 211221980 is 89122112.

211221980 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 2×211221980² = 89229449670240800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5280530 + ... + 5280569.

It is an arithmetic number, because the mean of its divisors is an integer number (36963850).

Almost surely, 2^211221980 is an apocalyptic number.

211221980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

211221980 is an abundant number, since it is smaller than the sum of its proper divisors (232344220).

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

211221980 is a wasteful number, since it uses less digits than its factorization.

211221980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10561108 (or 10561106 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 26.

The square root of 211221980 is about 14533.4779044797. The cubic root of 211221980 is about 595.5428795217.

The spelling of 211221980 in words is "two hundred eleven million, two hundred twenty-one thousand, nine hundred eighty".