21768708347 has 2 divisors, whose sum is σ = 21768708348. Its totient is φ = 21768708346.

The previous prime is 21768708343. The next prime is 21768708361. The reversal of 21768708347 is 74380786712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21768708347 - 2² = 21768708343 is a prime.

It is not a weakly prime, because it can be changed into another prime (21768708343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10884354173 + 10884354174.

It is an arithmetic number, because the mean of its divisors is an integer number (10884354174).

Almost surely, 2^21768708347 is an apocalyptic number.

21768708347 is a deficient number, since it is larger than the sum of its proper divisors (1).

21768708347 is an equidigital number, since it uses as much as digits as its factorization.

21768708347 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3161088, while the sum is 53.

The spelling of 21768708347 in words is "twenty-one billion, seven hundred sixty-eight million, seven hundred eight thousand, three hundred forty-seven".