21331743 has 4 divisors (see below), whose sum is σ = 28442328. Its totient is φ = 14221160.

The previous prime is 21331729. The next prime is 21331777. The reversal of 21331743 is 34713312.

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 21331743 - 2⁶ = 21331679 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21331043) 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, 3555288 + ... + 3555293.

It is an arithmetic number, because the mean of its divisors is an integer number (7110582).

Almost surely, 2^21331743 is an apocalyptic number.

21331743 is a deficient number, since it is larger than the sum of its proper divisors (7110585).

21331743 is an equidigital number, since it uses as much as digits as its factorization.

21331743 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7110584.

The product of its digits is 1512, while the sum is 24.

The square root of 21331743 is about 4618.6299916750. The cubic root of 21331743 is about 277.3376178468.

The spelling of 21331743 in words is "twenty-one million, three hundred thirty-one thousand, seven hundred forty-three".