21669873 has 8 divisors (see below), whose sum is σ = 29889600. Its totient is φ = 13948368.

The previous prime is 21669871. The next prime is 21669943. The reversal of 21669873 is 37896612.

It is a happy number.

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

It is not a de Polignac number, because 21669873 - 2¹ = 21669871 is a prime.

It is a super-2 number, since 2×21669873² = 939166791672258, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21669871) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 124453 + ... + 124626.

It is an arithmetic number, because the mean of its divisors is an integer number (3736200).

Almost surely, 2^21669873 is an apocalyptic number.

It is an amenable number.

21669873 is a deficient number, since it is larger than the sum of its proper divisors (8219727).

21669873 is a wasteful number, since it uses less digits than its factorization.

21669873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249111.

The product of its digits is 108864, while the sum is 42.

The square root of 21669873 is about 4655.0910839639. The cubic root of 21669873 is about 278.7953046943.

The spelling of 21669873 in words is "twenty-one million, six hundred sixty-nine thousand, eight hundred seventy-three".