21938043 has 4 divisors (see below), whose sum is σ = 29250728. Its totient is φ = 14625360.

The previous prime is 21938039. The next prime is 21938057. The reversal of 21938043 is 34083912.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21938043 - 2² = 21938039 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21938043.

It is not an unprimeable number, because it can be changed into a prime (21938023) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3656338 + ... + 3656343.

It is an arithmetic number, because the mean of its divisors is an integer number (7312682).

Almost surely, 2^21938043 is an apocalyptic number.

21938043 is a deficient number, since it is larger than the sum of its proper divisors (7312685).

21938043 is an equidigital number, since it uses as much as digits as its factorization.

21938043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7312684.

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 21938043 is about 4683.8064648318. The cubic root of 21938043 is about 279.9406464329.

The spelling of 21938043 in words is "twenty-one million, nine hundred thirty-eight thousand, forty-three".