21939711 has 8 divisors (see below), whose sum is σ = 29341104. Its totient is φ = 14582400.

The previous prime is 21939703. The next prime is 21939713. The reversal of 21939711 is 11793912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21939711 - 2³ = 21939703 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21939713) 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 7 ways as a sum of consecutive naturals, for example, 9840 + ... + 11861.

It is an arithmetic number, because the mean of its divisors is an integer number (3667638).

Almost surely, 2^21939711 is an apocalyptic number.

21939711 is a deficient number, since it is larger than the sum of its proper divisors (7401393).

21939711 is a wasteful number, since it uses less digits than its factorization.

21939711 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22041.

The product of its digits is 3402, while the sum is 33.

The square root of 21939711 is about 4683.9845217507. The cubic root of 21939711 is about 279.9477410974.

The spelling of 21939711 in words is "twenty-one million, nine hundred thirty-nine thousand, seven hundred eleven".