211221212220990 has 192 divisors, whose sum is σ = 610394611147776. Its totient is φ = 50403857366016.

The previous prime is 211221212220989. The next prime is 211221212221051. The reversal of 211221212220990 is 99022212122112.

211221212220990 is a `hidden beast` number, since 2 + 11 + 221 + 212 + 2 + 209 + 9 + 0 = 666.

It is a super-2 number, since 2×211221212220990² (a number of 29 digits) 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 95 ways as a sum of consecutive naturals, for example, 12094252 + ... + 23847711.

It is an arithmetic number, because the mean of its divisors is an integer number (3179138599728).

Almost surely, 2^{211221212220990} is an apocalyptic number.

211221212220990 is an abundant number, since it is smaller than the sum of its proper divisors (399173398926786).

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

211221212220990 is a wasteful number, since it uses less digits than its factorization.

211221212220990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35942183 (or 35942180 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The spelling of 211221212220990 in words is "two hundred eleven trillion, two hundred twenty-one billion, two hundred twelve million, two hundred twenty thousand, nine hundred ninety".