21423344347 has 2 divisors, whose sum is σ = 21423344348. Its totient is φ = 21423344346.

The previous prime is 21423344309. The next prime is 21423344351. The reversal of 21423344347 is 74344332412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21423344347 - 2¹¹ = 21423342299 is a prime.

It is not a weakly prime, because it can be changed into another prime (21423344357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10711672173 + 10711672174.

It is an arithmetic number, because the mean of its divisors is an integer number (10711672174).

Almost surely, 2^21423344347 is an apocalyptic number.

21423344347 is a deficient number, since it is larger than the sum of its proper divisors (1).

21423344347 is an equidigital number, since it uses as much as digits as its factorization.

21423344347 is an evil number, because the sum of its binary digits is even.

The product of its digits is 193536, while the sum is 37.

Adding to 21423344347 its reverse (74344332412), we get a palindrome (95767676759).

The spelling of 21423344347 in words is "twenty-one billion, four hundred twenty-three million, three hundred forty-four thousand, three hundred forty-seven".