211212920 has 64 divisors (see below), whose sum is σ = 499046400. Its totient is φ = 80346240.

The previous prime is 211212919. The next prime is 211212929. The reversal of 211212920 is 29212112.

It is a happy number.

It is a super-2 number, since 2×211212920² = 89221795149852800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 211212892 and 211212901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211212929) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 71717 + ... + 74603.

It is an arithmetic number, because the mean of its divisors is an integer number (7797600).

Almost surely, 2^211212920 is an apocalyptic number.

211212920 is a gapful number since it is divisible by the number (20) 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 211212920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (249523200).

211212920 is an abundant number, since it is smaller than the sum of its proper divisors (287833480).

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

211212920 is a wasteful number, since it uses less digits than its factorization.

211212920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2988 (or 2984 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 211212920 is about 14533.1662069901. The cubic root of 211212920 is about 595.5343644742.

The spelling of 211212920 in words is "two hundred eleven million, two hundred twelve thousand, nine hundred twenty".