21669238 has 16 divisors (see below), whose sum is σ = 33430320. Its totient is φ = 10528000.

The previous prime is 21669223. The next prime is 21669239. The reversal of 21669238 is 83296612.

It is a junction number, because it is equal to n+sod(n) for n = 21669197 and 21669206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21669239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32553 + ... + 33211.

It is an arithmetic number, because the mean of its divisors is an integer number (2089395).

Almost surely, 2^21669238 is an apocalyptic number.

21669238 is a deficient number, since it is larger than the sum of its proper divisors (11761082).

21669238 is a wasteful number, since it uses less digits than its factorization.

21669238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1103.

The product of its digits is 31104, while the sum is 37.

The square root of 21669238 is about 4655.0228785689. The cubic root of 21669238 is about 278.7925814551.

The spelling of 21669238 in words is "twenty-one million, six hundred sixty-nine thousand, two hundred thirty-eight".