181079021491 has 2 divisors, whose sum is σ = 181079021492. Its totient is φ = 181079021490.

The previous prime is 181079021471. The next prime is 181079021531. The reversal of 181079021491 is 194120970181.

181079021491 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 is a cyclic number.

It is not a de Polignac number, because 181079021491 - 2⁹ = 181079020979 is a prime.

It is a super-2 number, since 2×181079021491² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (181079021471) 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, 90539510745 + 90539510746.

It is an arithmetic number, because the mean of its divisors is an integer number (90539510746).

Almost surely, 2^181079021491 is an apocalyptic number.

181079021491 is a deficient number, since it is larger than the sum of its proper divisors (1).

181079021491 is an equidigital number, since it uses as much as digits as its factorization.

181079021491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 43.

The spelling of 181079021491 in words is "one hundred eighty-one billion, seventy-nine million, twenty-one thousand, four hundred ninety-one".