81167191459 has 16 divisors (see below), whose sum is σ = 84893677920. Its totient is φ = 77504313600.

The previous prime is 81167191453. The next prime is 81167191471. The reversal of 81167191459 is 95419176118.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 81167191459 - 2⁹ = 81167190947 is a prime.

It is a super-2 number, since 2×81167191459² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81167191453) 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 in 15 ways as a sum of consecutive naturals, for example, 2641327 + ... + 2671879.

It is an arithmetic number, because the mean of its divisors is an integer number (5305854870).

Almost surely, 2^81167191459 is an apocalyptic number.

81167191459 is a deficient number, since it is larger than the sum of its proper divisors (3726486461).

81167191459 is a wasteful number, since it uses less digits than its factorization.

81167191459 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31590.

The product of its digits is 544320, while the sum is 52.

The spelling of 81167191459 in words is "eighty-one billion, one hundred sixty-seven million, one hundred ninety-one thousand, four hundred fifty-nine".