21340433 has 4 divisors (see below), whose sum is σ = 22076340. Its totient is φ = 20604528.

The previous prime is 21340421. The next prime is 21340441. The reversal of 21340433 is 33404312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16875664 + 4464769 = 4108^2 + 2113^2 .

It is a cyclic number.

It is not a de Polignac number, because 21340433 - 2⁸ = 21340177 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21340633) 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, 367910 + ... + 367967.

It is an arithmetic number, because the mean of its divisors is an integer number (5519085).

Almost surely, 2^21340433 is an apocalyptic number.

It is an amenable number.

21340433 is a deficient number, since it is larger than the sum of its proper divisors (735907).

21340433 is an equidigital number, since it uses as much as digits as its factorization.

21340433 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 735906.

The product of its (nonzero) digits is 864, while the sum is 20.

The square root of 21340433 is about 4619.5706510454. The cubic root of 21340433 is about 277.3752727899.

Adding to 21340433 its reverse (33404312), we get a palindrome (54744745).

The spelling of 21340433 in words is "twenty-one million, three hundred forty thousand, four hundred thirty-three".