21242320443 has 16 divisors (see below), whose sum is σ = 31901204640. Its totient is φ = 13967551872.

The previous prime is 21242320439. The next prime is 21242320483. The reversal of 21242320443 is 34402324212.

21242320443 is a `hidden beast` number, since 212 + 4 + 2 + 3 + 2 + 0 + 443 = 666.

It is not a de Polignac number, because 21242320443 - 2² = 21242320439 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21242320483) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5386746 + ... + 5390687.

It is an arithmetic number, because the mean of its divisors is an integer number (1993825290).

Almost surely, 2^21242320443 is an apocalyptic number.

21242320443 is a deficient number, since it is larger than the sum of its proper divisors (10658884197).

21242320443 is a wasteful number, since it uses less digits than its factorization.

21242320443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10777515 (or 10777509 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 27.

Adding to 21242320443 its reverse (34402324212), we get a palindrome (55644644655).

The spelling of 21242320443 in words is "twenty-one billion, two hundred forty-two million, three hundred twenty thousand, four hundred forty-three".