211993866 has 48 divisors (see below), whose sum is σ = 526104384. Its totient is φ = 60435072.

The previous prime is 211993853. The next prime is 211993871. The reversal of 211993866 is 668399112.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 64290 + ... + 67506.

It is an arithmetic number, because the mean of its divisors is an integer number (10960508).

Almost surely, 2^211993866 is an apocalyptic number.

211993866 is an abundant number, since it is smaller than the sum of its proper divisors (314110518).

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

211993866 is a wasteful number, since it uses less digits than its factorization.

211993866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3755 (or 3752 counting only the distinct ones).

The product of its digits is 139968, while the sum is 45.

The square root of 211993866 is about 14560.0091346125. The cubic root of 211993866 is about 596.2674448702.

The spelling of 211993866 in words is "two hundred eleven million, nine hundred ninety-three thousand, eight hundred sixty-six".