2175868721647 has 2 divisors, whose sum is σ = 2175868721648. Its totient is φ = 2175868721646.

The previous prime is 2175868721641. The next prime is 2175868721659. The reversal of 2175868721647 is 7461278685712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2175868721647 - 2⁷ = 2175868721519 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2175868721641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1087934360823 + 1087934360824.

It is an arithmetic number, because the mean of its divisors is an integer number (1087934360824).

Almost surely, 2^{2175868721647} is an apocalyptic number.

2175868721647 is a deficient number, since it is larger than the sum of its proper divisors (1).

2175868721647 is an equidigital number, since it uses as much as digits as its factorization.

2175868721647 is an evil number, because the sum of its binary digits is even.

The product of its digits is 63221760, while the sum is 64.

The spelling of 2175868721647 in words is "two trillion, one hundred seventy-five billion, eight hundred sixty-eight million, seven hundred twenty-one thousand, six hundred forty-seven".