21669838 has 8 divisors (see below), whose sum is σ = 32742432. Its totient is φ = 10755696.

The previous prime is 21669829. The next prime is 21669871. The reversal of 21669838 is 83896612.

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 = 21669794 and 21669803.

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, 39270 + ... + 39817.

It is an arithmetic number, because the mean of its divisors is an integer number (4092804).

Almost surely, 2^21669838 is an apocalyptic number.

21669838 is a deficient number, since it is larger than the sum of its proper divisors (11072594).

21669838 is a wasteful number, since it uses less digits than its factorization.

21669838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79226.

The product of its digits is 124416, while the sum is 43.

The square root of 21669838 is about 4655.0873246374. The cubic root of 21669838 is about 278.7951545959.

The spelling of 21669838 in words is "twenty-one million, six hundred sixty-nine thousand, eight hundred thirty-eight".