21711724 has 12 divisors (see below), whose sum is σ = 39647664. Its totient is φ = 10383824.

The previous prime is 21711713. The next prime is 21711727. The reversal of 21711724 is 42711712.

It is not an unprimeable number, because it can be changed into a prime (21711727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 117907 + ... + 118090.

It is an arithmetic number, because the mean of its divisors is an integer number (3303972).

Almost surely, 2^21711724 is an apocalyptic number.

It is an amenable number.

21711724 is a deficient number, since it is larger than the sum of its proper divisors (17935940).

21711724 is a wasteful number, since it uses less digits than its factorization.

21711724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 236024 (or 236022 counting only the distinct ones).

The product of its digits is 784, while the sum is 25.

The square root of 21711724 is about 4659.5841016125. The cubic root of 21711724 is about 278.9746682893.

The spelling of 21711724 in words is "twenty-one million, seven hundred eleven thousand, seven hundred twenty-four".