81174401992 has 32 divisors (see below), whose sum is σ = 156059809920. Its totient is φ = 39565336000.

The previous prime is 81174401981. The next prime is 81174402017. The reversal of 81174401992 is 29910447118.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 335683 + ... + 524434.

It is an arithmetic number, because the mean of its divisors is an integer number (4876869060).

Almost surely, 2^81174401992 is an apocalyptic number.

It is an amenable number.

81174401992 is a deficient number, since it is larger than the sum of its proper divisors (74885407928).

81174401992 is a wasteful number, since it uses less digits than its factorization.

81174401992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 860421 (or 860417 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 46.

The spelling of 81174401992 in words is "eighty-one billion, one hundred seventy-four million, four hundred one thousand, nine hundred ninety-two".