21682206 has 144 divisors (see below), whose sum is σ = 61746048. Its totient is φ = 5443200.

The previous prime is 21682201. The next prime is 21682223. The reversal of 21682206 is 60228612.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21682206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21682201) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 355416 + ... + 355476.

It is an arithmetic number, because the mean of its divisors is an integer number (428792).

Almost surely, 2^21682206 is an apocalyptic number.

21682206 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21682206, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30873024).

21682206 is an abundant number, since it is smaller than the sum of its proper divisors (40063842).

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

21682206 is a wasteful number, since it uses less digits than its factorization.

21682206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127 (or 117 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 21682206 is about 4656.4155742373. The cubic root of 21682206 is about 278.8481850289.

The spelling of 21682206 in words is "twenty-one million, six hundred eighty-two thousand, two hundred six".