21633669 has 8 divisors (see below), whose sum is σ = 32049920. Its totient is φ = 14422428.

The previous prime is 21633653. The next prime is 21633671. The reversal of 21633669 is 96633612.

It is not a de Polignac number, because 21633669 - 2⁴ = 21633653 is a prime.

It is a super-2 number, since 2×21633669² = 936031268803122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21633649) 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, 400597 + ... + 400650.

It is an arithmetic number, because the mean of its divisors is an integer number (4006240).

Almost surely, 2^21633669 is an apocalyptic number.

It is an amenable number.

21633669 is a deficient number, since it is larger than the sum of its proper divisors (10416251).

21633669 is an equidigital number, since it uses as much as digits as its factorization.

21633669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 801256 (or 801250 counting only the distinct ones).

The product of its digits is 34992, while the sum is 36.

The square root of 21633669 is about 4651.2008126934. The cubic root of 21633669 is about 278.6399564292.

It can be divided in two parts, 2163 and 3669, that added together give a cube (5832 = 18³).

The spelling of 21633669 in words is "twenty-one million, six hundred thirty-three thousand, six hundred sixty-nine".