21638822 has 8 divisors (see below), whose sum is σ = 32745816. Its totient is φ = 10723552.

The previous prime is 21638819. The next prime is 21638831. The reversal of 21638822 is 22883612.

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, 47648 + ... + 48099.

It is an arithmetic number, because the mean of its divisors is an integer number (4093227).

Almost surely, 2^21638822 is an apocalyptic number.

21638822 is a deficient number, since it is larger than the sum of its proper divisors (11106994).

21638822 is a wasteful number, since it uses less digits than its factorization.

21638822 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95862.

The product of its digits is 9216, while the sum is 32.

The square root of 21638822 is about 4651.7547226826. The cubic root of 21638822 is about 278.6620780845.

The spelling of 21638822 in words is "twenty-one million, six hundred thirty-eight thousand, eight hundred twenty-two".