211866864 has 160 divisors (see below), whose sum is σ = 622888704. Its totient is φ = 61501440.

The previous prime is 211866859. The next prime is 211866871. The reversal of 211866864 is 468668112.

It is a super-2 number, since 2×211866864² = 89775136122388992, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1874872 + ... + 1874984.

Almost surely, 2^211866864 is an apocalyptic number.

211866864 is a gapful number since it is divisible by the number (24) 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 211866864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (311444352).

211866864 is an abundant number, since it is smaller than the sum of its proper divisors (411021840).

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

211866864 is a wasteful number, since it uses less digits than its factorization.

211866864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255 (or 249 counting only the distinct ones).

The product of its digits is 110592, while the sum is 42.

The square root of 211866864 is about 14555.6471515354. The cubic root of 211866864 is about 596.1483497806.

The spelling of 211866864 in words is "two hundred eleven million, eight hundred sixty-six thousand, eight hundred sixty-four".