21545422 has 8 divisors (see below), whose sum is σ = 32368176. Its totient is φ = 10756032.

The previous prime is 21545393. The next prime is 21545429. The reversal of 21545422 is 22454512.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21545429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6658 + ... + 9349.

It is an arithmetic number, because the mean of its divisors is an integer number (4046022).

Almost surely, 2^21545422 is an apocalyptic number.

21545422 is a deficient number, since it is larger than the sum of its proper divisors (10822754).

21545422 is a wasteful number, since it uses less digits than its factorization.

21545422 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16682.

The product of its digits is 3200, while the sum is 25.

The square root of 21545422 is about 4641.7046437704. The cubic root of 21545422 is about 278.2605686258.

Adding to 21545422 its reverse (22454512), we get a palindrome (43999934).

The spelling of 21545422 in words is "twenty-one million, five hundred forty-five thousand, four hundred twenty-two".