21642206 has 16 divisors (see below), whose sum is σ = 33112464. Its totient is φ = 10606464.

The previous prime is 21642199. The next prime is 21642217. The reversal of 21642206 is 60224612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49766 + ... + 50198.

It is an arithmetic number, because the mean of its divisors is an integer number (2069529).

Almost surely, 2^21642206 is an apocalyptic number.

21642206 is a deficient number, since it is larger than the sum of its proper divisors (11470258).

21642206 is a wasteful number, since it uses less digits than its factorization.

21642206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 875.

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 21642206 is about 4652.1184421723. The cubic root of 21642206 is about 278.6766035721.

Adding to 21642206 its reverse (60224612), we get a palindrome (81866818).

The spelling of 21642206 in words is "twenty-one million, six hundred forty-two thousand, two hundred six".