211668390 has 80 divisors (see below), whose sum is σ = 588844080. Its totient is φ = 54492480.

The previous prime is 211668389. The next prime is 211668409. The reversal of 211668390 is 93866112.

211668390 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 18985 + ... + 27995.

It is an arithmetic number, because the mean of its divisors is an integer number (7360551).

Almost surely, 2^211668390 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 211668390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (294422040).

211668390 is an abundant number, since it is smaller than the sum of its proper divisors (377175690).

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

211668390 is a wasteful number, since it uses less digits than its factorization.

211668390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9059 (or 9050 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 211668390 is about 14548.8277878323. The cubic root of 211668390 is about 595.9621370629.

The spelling of 211668390 in words is "two hundred eleven million, six hundred sixty-eight thousand, three hundred ninety".