167891125421 has 2 divisors, whose sum is σ = 167891125422. Its totient is φ = 167891125420.

The previous prime is 167891125387. The next prime is 167891125483. The reversal of 167891125421 is 124521198761.

167891125421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 166557853225 + 1333272196 = 408115^2 + 36514^2 .

It is a cyclic number.

It is not a de Polignac number, because 167891125421 - 2⁶ = 167891125357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (167891124421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83945562710 + 83945562711.

It is an arithmetic number, because the mean of its divisors is an integer number (83945562711).

Almost surely, 2^167891125421 is an apocalyptic number.

It is an amenable number.

167891125421 is a deficient number, since it is larger than the sum of its proper divisors (1).

167891125421 is an equidigital number, since it uses as much as digits as its factorization.

167891125421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 241920, while the sum is 47.

The spelling of 167891125421 in words is "one hundred sixty-seven billion, eight hundred ninety-one million, one hundred twenty-five thousand, four hundred twenty-one".