221170825871 has 2 divisors, whose sum is σ = 221170825872. Its totient is φ = 221170825870.

The previous prime is 221170825831. The next prime is 221170825873. The reversal of 221170825871 is 178528071122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221170825871 - 2⁶ = 221170825807 is a prime.

Together with 221170825873, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221170825873) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110585412935 + 110585412936.

It is an arithmetic number, because the mean of its divisors is an integer number (110585412936).

Almost surely, 2^221170825871 is an apocalyptic number.

221170825871 is a deficient number, since it is larger than the sum of its proper divisors (1).

221170825871 is an equidigital number, since it uses as much as digits as its factorization.

221170825871 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 125440, while the sum is 44.

Adding to 221170825871 its reverse (178528071122), we get a palindrome (399698896993).

The spelling of 221170825871 in words is "two hundred twenty-one billion, one hundred seventy million, eight hundred twenty-five thousand, eight hundred seventy-one".