21339743 has 4 divisors (see below), whose sum is σ = 22595040. Its totient is φ = 20084448.

The previous prime is 21339733. The next prime is 21339751. The reversal of 21339743 is 34793312.

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 21339743 - 2¹² = 21335647 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21339733) 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, 627623 + ... + 627656.

It is an arithmetic number, because the mean of its divisors is an integer number (5648760).

Almost surely, 2^21339743 is an apocalyptic number.

21339743 is a deficient number, since it is larger than the sum of its proper divisors (1255297).

21339743 is a wasteful number, since it uses less digits than its factorization.

21339743 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1255296.

The product of its digits is 13608, while the sum is 32.

The square root of 21339743 is about 4619.4959681766. The cubic root of 21339743 is about 277.3722833004.

The spelling of 21339743 in words is "twenty-one million, three hundred thirty-nine thousand, seven hundred forty-three".