21740543 has 8 divisors (see below), whose sum is σ = 24748416. Its totient is φ = 18904600.

The previous prime is 21740539. The next prime is 21740549. The reversal of 21740543 is 34504712.

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

It is not a de Polignac number, because 21740543 - 2² = 21740539 is a prime.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21740549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42713 + ... + 43218.

It is an arithmetic number, because the mean of its divisors is an integer number (3093552).

Almost surely, 2^21740543 is an apocalyptic number.

21740543 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21740543 is a deficient number, since it is larger than the sum of its proper divisors (3007873).

21740543 is a wasteful number, since it uses less digits than its factorization.

21740543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85965.

The product of its (nonzero) digits is 3360, while the sum is 26.

The square root of 21740543 is about 4662.6755194845. The cubic root of 21740543 is about 279.0980458156.

The spelling of 21740543 in words is "twenty-one million, seven hundred forty thousand, five hundred forty-three".