21442340233 has 4 divisors (see below), whose sum is σ = 22021862980. Its totient is φ = 20862817488.

The previous prime is 21442340209. The next prime is 21442340251. The reversal of 21442340233 is 33204324412.

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 11886886729 + 9555453504 = 109027^2 + 97752^2 .

It is a cyclic number.

It is not a de Polignac number, because 21442340233 - 2⁵ = 21442340201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21442340273) 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, 289761318 + ... + 289761391.

It is an arithmetic number, because the mean of its divisors is an integer number (5505465745).

Almost surely, 2^21442340233 is an apocalyptic number.

It is an amenable number.

21442340233 is a deficient number, since it is larger than the sum of its proper divisors (579522747).

21442340233 is an equidigital number, since it uses as much as digits as its factorization.

21442340233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 579522746.

The product of its (nonzero) digits is 13824, while the sum is 28.

Adding to 21442340233 its reverse (33204324412), we get a palindrome (54646664645).

It can be divided in two parts, 21442 and 340233, that added together give a triangular number (361675 = T₈₅₀).

The spelling of 21442340233 in words is "twenty-one billion, four hundred forty-two million, three hundred forty thousand, two hundred thirty-three".