21564706 has 8 divisors (see below), whose sum is σ = 32379984. Its totient is φ = 10771380.

The previous prime is 21564703. The next prime is 21564707. The reversal of 21564706 is 60746512.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21564703) 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, 2760 + ... + 7123.

It is an arithmetic number, because the mean of its divisors is an integer number (4047498).

Almost surely, 2^21564706 is an apocalyptic number.

21564706 is a deficient number, since it is larger than the sum of its proper divisors (10815278).

21564706 is a wasteful number, since it uses less digits than its factorization.

21564706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10976.

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 21564706 is about 4643.7814332718. The cubic root of 21564706 is about 278.3435619207.

The spelling of 21564706 in words is "twenty-one million, five hundred sixty-four thousand, seven hundred six".