21940212 has 96 divisors (see below), whose sum is σ = 62899200. Its totient is φ = 5812992.

The previous prime is 21940201. The next prime is 21940241. The reversal of 21940212 is 21204912.

It is a Harshad number since it is a multiple of its sum of digits (21).

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, 94048 + ... + 94280.

It is an arithmetic number, because the mean of its divisors is an integer number (655200).

Almost surely, 2^21940212 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21940212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31449600).

21940212 is an abundant number, since it is smaller than the sum of its proper divisors (40958988).

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

21940212 is a wasteful number, since it uses less digits than its factorization.

21940212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 325 (or 323 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 21940212 is about 4684.0380015538. The cubic root of 21940212 is about 279.9498719786.

The spelling of 21940212 in words is "twenty-one million, nine hundred forty thousand, two hundred twelve".