21885638 has 8 divisors (see below), whose sum is σ = 33046320. Its totient is φ = 10870200.

The previous prime is 21885631. The next prime is 21885649. The reversal of 21885638 is 83658812.

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

It is a junction number, because it is equal to n+sod(n) for n = 21885595 and 21885604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21885631) 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, 35933 + ... + 36536.

It is an arithmetic number, because the mean of its divisors is an integer number (4130790).

Almost surely, 2^21885638 is an apocalyptic number.

21885638 is a deficient number, since it is larger than the sum of its proper divisors (11160682).

21885638 is a wasteful number, since it uses less digits than its factorization.

21885638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72622.

The product of its digits is 92160, while the sum is 41.

The square root of 21885638 is about 4678.2088452740. The cubic root of 21885638 is about 279.7175638417.

The spelling of 21885638 in words is "twenty-one million, eight hundred eighty-five thousand, six hundred thirty-eight".