21544242 has 8 divisors (see below), whose sum is σ = 43088496. Its totient is φ = 7181412.

The previous prime is 21544231. The next prime is 21544273. The reversal of 21544242 is 24244512.

It is a happy number.

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

21544242 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1795348 + ... + 1795359.

It is an arithmetic number, because the mean of its divisors is an integer number (5386062).

Almost surely, 2^21544242 is an apocalyptic number.

21544242 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21544242 is a wasteful number, since it uses less digits than its factorization.

21544242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3590712.

The product of its digits is 2560, while the sum is 24.

The square root of 21544242 is about 4641.5775335547. The cubic root of 21544242 is about 278.2554886067.

Adding to 21544242 its reverse (24244512), we get a palindrome (45788754).

The spelling of 21544242 in words is "twenty-one million, five hundred forty-four thousand, two hundred forty-two".