21693444 has 24 divisors (see below), whose sum is σ = 50695008. Its totient is φ = 7220160.

The previous prime is 21693437. The next prime is 21693493. The reversal of 21693444 is 44439612.

It is a super-2 number, since 2×21693444² = 941211025162272, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12264 + ... + 13920.

It is an arithmetic number, because the mean of its divisors is an integer number (2112292).

Almost surely, 2^21693444 is an apocalyptic number.

It is an amenable number.

21693444 is an abundant number, since it is smaller than the sum of its proper divisors (29001564).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21693444 is a wasteful number, since it uses less digits than its factorization.

21693444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2755 (or 2753 counting only the distinct ones).

The product of its digits is 20736, while the sum is 33.

The square root of 21693444 is about 4657.6221401054. The cubic root of 21693444 is about 278.8963528622.

The spelling of 21693444 in words is "twenty-one million, six hundred ninety-three thousand, four hundred forty-four".