21806926 has 4 divisors (see below), whose sum is σ = 32710392. Its totient is φ = 10903462.

The previous prime is 21806909. The next prime is 21806929. The reversal of 21806926 is 62960812.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 21806891 and 21806900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21806929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5451730 + ... + 5451733.

It is an arithmetic number, because the mean of its divisors is an integer number (8177598).

Almost surely, 2^21806926 is an apocalyptic number.

21806926 is a deficient number, since it is larger than the sum of its proper divisors (10903466).

21806926 is a wasteful number, since it uses less digits than its factorization.

21806926 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10903465.

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 21806926 is about 4669.7886461809. The cubic root of 21806926 is about 279.3818249930.

The spelling of 21806926 in words is "twenty-one million, eight hundred six thousand, nine hundred twenty-six".