21440943 has 20 divisors (see below), whose sum is σ = 32259568. Its totient is φ = 14191200.

The previous prime is 21440941. The next prime is 21440989. The reversal of 21440943 is 34904412.

21440943 is a `hidden beast` number, since 214 + 409 + 43 = 666.

It is not a de Polignac number, because 21440943 - 2¹ = 21440941 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21440941) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 11355 + ... + 13107.

Almost surely, 2^21440943 is an apocalyptic number.

21440943 is a deficient number, since it is larger than the sum of its proper divisors (10818625).

21440943 is a wasteful number, since it uses less digits than its factorization.

21440943 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1916 (or 1907 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 21440943 is about 4630.4365884871. The cubic root of 21440943 is about 277.8100551944.

The spelling of 21440943 in words is "twenty-one million, four hundred forty thousand, nine hundred forty-three".