21689246 has 16 divisors (see below), whose sum is σ = 35290080. Its totient is φ = 9957120.

The previous prime is 21689237. The next prime is 21689257. The reversal of 21689246 is 64298612.

It is a Curzon number.

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, 6386 + ... + 9173.

It is an arithmetic number, because the mean of its divisors is an integer number (2205630).

Almost surely, 2^21689246 is an apocalyptic number.

21689246 is a deficient number, since it is larger than the sum of its proper divisors (13600834).

21689246 is a wasteful number, since it uses less digits than its factorization.

21689246 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15619.

The product of its digits is 41472, while the sum is 38.

The square root of 21689246 is about 4657.1714591584. The cubic root of 21689246 is about 278.8783615216.

The spelling of 21689246 in words is "twenty-one million, six hundred eighty-nine thousand, two hundred forty-six".