21852543 has 4 divisors (see below), whose sum is σ = 29136728. Its totient is φ = 14568360.

The previous prime is 21852539. The next prime is 21852547. The reversal of 21852543 is 34525812.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21852539) and next prime (21852547).

It is not a de Polignac number, because 21852543 - 2² = 21852539 is a prime.

It is an alternating number because its digits alternate between even and odd.

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 21852543.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21852547) 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, 3642088 + ... + 3642093.

It is an arithmetic number, because the mean of its divisors is an integer number (7284182).

Almost surely, 2^21852543 is an apocalyptic number.

21852543 is a deficient number, since it is larger than the sum of its proper divisors (7284185).

21852543 is an equidigital number, since it uses as much as digits as its factorization.

21852543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7284184.

The product of its digits is 9600, while the sum is 30.

The square root of 21852543 is about 4674.6703627101. The cubic root of 21852543 is about 279.5764983797.

The spelling of 21852543 in words is "twenty-one million, eight hundred fifty-two thousand, five hundred forty-three".