21142206 has 24 divisors (see below), whose sum is σ = 46121400. Its totient is φ = 6999216.

The previous prime is 21142201. The next prime is 21142213. The reversal of 21142206 is 60224112.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21142201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1260 + ... + 6623.

It is an arithmetic number, because the mean of its divisors is an integer number (1921725).

Almost surely, 2^21142206 is an apocalyptic number.

21142206 is an abundant number, since it is smaller than the sum of its proper divisors (24979194).

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

21142206 is a wasteful number, since it uses less digits than its factorization.

21142206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8040 (or 8037 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 21142206 is about 4598.0654627789. The cubic root of 21142206 is about 276.5137720720.

Adding to 21142206 its reverse (60224112), we get a palindrome (81366318).

The spelling of 21142206 in words is "twenty-one million, one hundred forty-two thousand, two hundred six".