21938071 has 4 divisors (see below), whose sum is σ = 22036672. Its totient is φ = 21839472.

The previous prime is 21938057. The next prime is 21938083. The reversal of 21938071 is 17083912.

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

It is a cyclic number.

It is not a de Polignac number, because 21938071 - 2⁵ = 21938039 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21938771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48966 + ... + 49411.

It is an arithmetic number, because the mean of its divisors is an integer number (5509168).

Almost surely, 2^21938071 is an apocalyptic number.

21938071 is a deficient number, since it is larger than the sum of its proper divisors (98601).

21938071 is an equidigital number, since it uses as much as digits as its factorization.

21938071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98600.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 21938071 is about 4683.8094538527. The cubic root of 21938071 is about 279.9407655310.

The spelling of 21938071 in words is "twenty-one million, nine hundred thirty-eight thousand, seventy-one".