21443223031 has 4 divisors (see below), whose sum is σ = 21479022000. Its totient is φ = 21407424064.

The previous prime is 21443223029. The next prime is 21443223059. The reversal of 21443223031 is 13032234412.

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

It is a cyclic number.

It is not a de Polignac number, because 21443223031 - 2¹ = 21443223029 is a prime.

It is a super-2 number, since 2×21443223031² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21443222987 and 21443223005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21443253031) 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, 17898586 + ... + 17899783.

It is an arithmetic number, because the mean of its divisors is an integer number (5369755500).

Almost surely, 2^21443223031 is an apocalyptic number.

21443223031 is a deficient number, since it is larger than the sum of its proper divisors (35798969).

21443223031 is an equidigital number, since it uses as much as digits as its factorization.

21443223031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35798968.

The product of its (nonzero) digits is 3456, while the sum is 25.

Adding to 21443223031 its reverse (13032234412), we get a palindrome (34475457443).

The spelling of 21443223031 in words is "twenty-one billion, four hundred forty-three million, two hundred twenty-three thousand, thirty-one".