21711743 has 4 divisors (see below), whose sum is σ = 21723768. Its totient is φ = 21699720.

The previous prime is 21711731. The next prime is 21711757. The reversal of 21711743 is 34711712.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21711743 - 2⁴ = 21711727 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 (21711713) 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, 2693 + ... + 7118.

It is an arithmetic number, because the mean of its divisors is an integer number (5430942).

Almost surely, 2^21711743 is an apocalyptic number.

21711743 is a deficient number, since it is larger than the sum of its proper divisors (12025).

21711743 is an equidigital number, since it uses as much as digits as its factorization.

21711743 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12024.

The product of its digits is 1176, while the sum is 26.

The square root of 21711743 is about 4659.5861404206. The cubic root of 21711743 is about 278.9747496665.

The spelling of 21711743 in words is "twenty-one million, seven hundred eleven thousand, seven hundred forty-three".