21896566 has 8 divisors (see below), whose sum is σ = 33977520. Its totient is φ = 10570728.

The previous prime is 21896543. The next prime is 21896597. The reversal of 21896566 is 66569812.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 188706 + ... + 188821.

It is an arithmetic number, because the mean of its divisors is an integer number (4247190).

Almost surely, 2^21896566 is an apocalyptic number.

21896566 is a deficient number, since it is larger than the sum of its proper divisors (12080954).

21896566 is a wasteful number, since it uses less digits than its factorization.

21896566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 377558.

The product of its digits is 155520, while the sum is 43.

The square root of 21896566 is about 4679.3766678907. The cubic root of 21896566 is about 279.7641125557.

The spelling of 21896566 in words is "twenty-one million, eight hundred ninety-six thousand, five hundred sixty-six".