21333461 has 4 divisors (see below), whose sum is σ = 21829632. Its totient is φ = 20837292.

The previous prime is 21333451. The next prime is 21333467. The reversal of 21333461 is 16433312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21333461 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21333467) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 248021 + ... + 248106.

It is an arithmetic number, because the mean of its divisors is an integer number (5457408).

Almost surely, 2^21333461 is an apocalyptic number.

It is an amenable number.

21333461 is a deficient number, since it is larger than the sum of its proper divisors (496171).

21333461 is an equidigital number, since it uses as much as digits as its factorization.

21333461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 496170.

The product of its digits is 1296, while the sum is 23.

The square root of 21333461 is about 4618.8159738184. The cubic root of 21333461 is about 277.3450629837.

Adding to 21333461 its reverse (16433312), we get a palindrome (37766773).

The spelling of 21333461 in words is "twenty-one million, three hundred thirty-three thousand, four hundred sixty-one".