21442444431 has 4 divisors (see below), whose sum is σ = 28589925912. Its totient is φ = 14294962952.

The previous prime is 21442444421. The next prime is 21442444447. The reversal of 21442444431 is 13444424412.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21442444431 is a prime.

It is a super-2 number, since 2×21442444431² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21442444392 and 21442444401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21442444411) 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, 3573740736 + ... + 3573740741.

It is an arithmetic number, because the mean of its divisors is an integer number (7147481478).

Almost surely, 2^21442444431 is an apocalyptic number.

21442444431 is a deficient number, since it is larger than the sum of its proper divisors (7147481481).

21442444431 is an equidigital number, since it uses as much as digits as its factorization.

21442444431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7147481480.

The product of its digits is 49152, while the sum is 33.

Adding to 21442444431 its reverse (13444424412), we get a palindrome (34886868843).

The spelling of 21442444431 in words is "twenty-one billion, four hundred forty-two million, four hundred forty-four thousand, four hundred thirty-one".