21741543 has 12 divisors (see below), whose sum is σ = 31758480. Its totient is φ = 14330976.

The previous prime is 21741541. The next prime is 21741553. The reversal of 21741543 is 34514712.

It is not a de Polignac number, because 21741543 - 2¹ = 21741541 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21741541) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12771 + ... + 14372.

It is an arithmetic number, because the mean of its divisors is an integer number (2646540).

Almost surely, 2^21741543 is an apocalyptic number.

21741543 is a deficient number, since it is larger than the sum of its proper divisors (10016937).

21741543 is a wasteful number, since it uses less digits than its factorization.

21741543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27238 (or 27235 counting only the distinct ones).

The product of its digits is 3360, while the sum is 27.

The square root of 21741543 is about 4662.7827528205. The cubic root of 21741543 is about 279.1023249753.

The spelling of 21741543 in words is "twenty-one million, seven hundred forty-one thousand, five hundred forty-three".