21433121 has 8 divisors (see below), whose sum is σ = 23289600. Its totient is φ = 19649520.

The previous prime is 21433103. The next prime is 21433123. The reversal of 21433121 is 12133412.

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 21433121 - 2⁶ = 21433057 is a prime.

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 21433121.

It is not an unprimeable number, because it can be changed into a prime (21433123) 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, 17606 + ... + 18783.

It is an arithmetic number, because the mean of its divisors is an integer number (2911200).

Almost surely, 2^21433121 is an apocalyptic number.

It is an amenable number.

21433121 is a deficient number, since it is larger than the sum of its proper divisors (1856479).

21433121 is a wasteful number, since it uses less digits than its factorization.

21433121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36439.

The product of its digits is 144, while the sum is 17.

The square root of 21433121 is about 4629.5918826609. The cubic root of 21433121 is about 277.7762678970.

Adding to 21433121 its reverse (12133412), we get a palindrome (33566533).

The spelling of 21433121 in words is "twenty-one million, four hundred thirty-three thousand, one hundred twenty-one".