21543042 has 16 divisors (see below), whose sum is σ = 44959680. Its totient is φ = 6868752.

The previous prime is 21543031. The next prime is 21543077. The reversal of 21543042 is 24034512.

It is a super-2 number, since 2×21543042² = 928205317227528, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77917 + ... + 78192.

It is an arithmetic number, because the mean of its divisors is an integer number (2809980).

Almost surely, 2^21543042 is an apocalyptic number.

21543042 is an abundant number, since it is smaller than the sum of its proper divisors (23416638).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21543042 is a wasteful number, since it uses less digits than its factorization.

21543042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156137.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 21543042 is about 4641.4482653586. The cubic root of 21543042 is about 278.2503222954.

Adding to 21543042 its reverse (24034512), we get a palindrome (45577554).

The spelling of 21543042 in words is "twenty-one million, five hundred forty-three thousand, forty-two".