21000332347 has 2 divisors, whose sum is σ = 21000332348. Its totient is φ = 21000332346.

The previous prime is 21000332341. The next prime is 21000332357. The reversal of 21000332347 is 74323300012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21000332347 - 2⁷ = 21000332219 is a prime.

It is not a weakly prime, because it can be changed into another prime (21000332341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500166173 + 10500166174.

It is an arithmetic number, because the mean of its divisors is an integer number (10500166174).

Almost surely, 2^21000332347 is an apocalyptic number.

21000332347 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000332347 is an equidigital number, since it uses as much as digits as its factorization.

21000332347 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024, while the sum is 25.

Adding to 21000332347 its reverse (74323300012), we get a palindrome (95323632359).

The spelling of 21000332347 in words is "twenty-one billion, three hundred thirty-two thousand, three hundred forty-seven".