21546543 has 8 divisors (see below), whose sum is σ = 29505328. Its totient is φ = 13976064.

The previous prime is 21546533. The next prime is 21546557. The reversal of 21546543 is 34564512.

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

It is not a de Polignac number, because 21546543 - 2⁴ = 21546527 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21546543.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21546533) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 96946 + ... + 97167.

It is an arithmetic number, because the mean of its divisors is an integer number (3688166).

Almost surely, 2^21546543 is an apocalyptic number.

21546543 is a deficient number, since it is larger than the sum of its proper divisors (7958785).

21546543 is a wasteful number, since it uses less digits than its factorization.

21546543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194153.

The product of its digits is 14400, while the sum is 30.

The square root of 21546543 is about 4641.8253952513. The cubic root of 21546543 is about 278.2653944722.

The spelling of 21546543 in words is "twenty-one million, five hundred forty-six thousand, five hundred forty-three".