21868443 has 24 divisors (see below), whose sum is σ = 34358688. Its totient is φ = 13347072.

The previous prime is 21868433. The next prime is 21868447. The reversal of 21868443 is 34486812.

It is not a de Polignac number, because 21868443 - 2⁹ = 21867931 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21868398 and 21868407.

It is not an unprimeable number, because it can be changed into a prime (21868447) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3730 + ... + 7592.

It is an arithmetic number, because the mean of its divisors is an integer number (1431612).

Almost surely, 2^21868443 is an apocalyptic number.

21868443 is a deficient number, since it is larger than the sum of its proper divisors (12490245).

21868443 is a wasteful number, since it uses less digits than its factorization.

21868443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3923 (or 3920 counting only the distinct ones).

The product of its digits is 36864, while the sum is 36.

The square root of 21868443 is about 4676.3707081454. The cubic root of 21868443 is about 279.6442889435.

The spelling of 21868443 in words is "twenty-one million, eight hundred sixty-eight thousand, four hundred forty-three".