21321104447 has 2 divisors, whose sum is σ = 21321104448. Its totient is φ = 21321104446.

The previous prime is 21321104407. The next prime is 21321104461. The reversal of 21321104447 is 74440112312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21321104447 - 2⁶ = 21321104383 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21321104407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10660552223 + 10660552224.

It is an arithmetic number, because the mean of its divisors is an integer number (10660552224).

Almost surely, 2^21321104447 is an apocalyptic number.

21321104447 is a deficient number, since it is larger than the sum of its proper divisors (1).

21321104447 is an equidigital number, since it uses as much as digits as its factorization.

21321104447 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5376, while the sum is 29.

Adding to 21321104447 its reverse (74440112312), we get a palindrome (95761216759).

The spelling of 21321104447 in words is "twenty-one billion, three hundred twenty-one million, one hundred four thousand, four hundred forty-seven".