21442553 has 8 divisors (see below), whose sum is σ = 23577600. Its totient is φ = 19338480.

The previous prime is 21442543. The next prime is 21442591. The reversal of 21442553 is 35524412.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21442553 - 2⁶ = 21442489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21442543) 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, 6278 + ... + 9071.

It is an arithmetic number, because the mean of its divisors is an integer number (2947200).

Almost surely, 2^21442553 is an apocalyptic number.

It is an amenable number.

21442553 is a deficient number, since it is larger than the sum of its proper divisors (2135047).

21442553 is a wasteful number, since it uses less digits than its factorization.

21442553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15487.

The product of its digits is 4800, while the sum is 26.

The square root of 21442553 is about 4630.6104349211. The cubic root of 21442553 is about 277.8170086043.

Adding to 21442553 its reverse (35524412), we get a palindrome (56966965).

The spelling of 21442553 in words is "twenty-one million, four hundred forty-two thousand, five hundred fifty-three".