21806060 has 12 divisors (see below), whose sum is σ = 45792768. Its totient is φ = 8722416.

The previous prime is 21806041. The next prime is 21806063. The reversal of 21806060 is 6060812.

It is a hoax number, since the sum of its digits (23) coincides with the sum of the digits of its distinct prime factors.

21806060 is a modest number, since divided by 6060 gives 2180 as remainder.

It is not an unprimeable number, because it can be changed into a prime (21806063) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 545132 + ... + 545171.

It is an arithmetic number, because the mean of its divisors is an integer number (3816064).

Almost surely, 2^21806060 is an apocalyptic number.

21806060 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21806060 is an abundant number, since it is smaller than the sum of its proper divisors (23986708).

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

21806060 is a wasteful number, since it uses less digits than its factorization.

21806060 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1090312 (or 1090310 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 21806060 is about 4669.6959215778. The cubic root of 21806060 is about 279.3781266593.

Adding to 21806060 its reverse (6060812), we get a palindrome (27866872).

The spelling of 21806060 in words is "twenty-one million, eight hundred six thousand, sixty".