21143240347 has 2 divisors, whose sum is σ = 21143240348. Its totient is φ = 21143240346.

The previous prime is 21143240297. The next prime is 21143240359. The reversal of 21143240347 is 74304234112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21143240347 is a prime.

It is a super-2 number, since 2×21143240347² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21143240747) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10571620173 + 10571620174.

It is an arithmetic number, because the mean of its divisors is an integer number (10571620174).

Almost surely, 2^21143240347 is an apocalyptic number.

21143240347 is a deficient number, since it is larger than the sum of its proper divisors (1).

21143240347 is an equidigital number, since it uses as much as digits as its factorization.

21143240347 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16128, while the sum is 31.

Adding to 21143240347 its reverse (74304234112), we get a palindrome (95447474459).

The spelling of 21143240347 in words is "twenty-one billion, one hundred forty-three million, two hundred forty thousand, three hundred forty-seven".