167191885907821 has 2 divisors, whose sum is σ = 167191885907822. Its totient is φ = 167191885907820.

The previous prime is 167191885907803. The next prime is 167191885907831. The reversal of 167191885907821 is 128709588191761.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 110788992153225 + 56402893754596 = 10525635^2 + 7510186^2 .

It is a cyclic number.

It is not a de Polignac number, because 167191885907821 - 2¹³ = 167191885899629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (167191885907831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83595942953910 + 83595942953911.

It is an arithmetic number, because the mean of its divisors is an integer number (83595942953911).

Almost surely, 2^{167191885907821} is an apocalyptic number.

It is an amenable number.

167191885907821 is a deficient number, since it is larger than the sum of its proper divisors (1).

167191885907821 is an equidigital number, since it uses as much as digits as its factorization.

167191885907821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 121927680, while the sum is 73.

The spelling of 167191885907821 in words is "one hundred sixty-seven trillion, one hundred ninety-one billion, eight hundred eighty-five million, nine hundred seven thousand, eight hundred twenty-one".