81367792 has 40 divisors (see below), whose sum is σ = 172488960. Its totient is φ = 36876480.

The previous prime is 81367753. The next prime is 81367799. The reversal of 81367792 is 29776318.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81367799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 112809 + ... + 113527.

It is an arithmetic number, because the mean of its divisors is an integer number (4312224).

Almost surely, 2^81367792 is an apocalyptic number.

It is an amenable number.

81367792 is an abundant number, since it is smaller than the sum of its proper divisors (91121168).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81367792 is a wasteful number, since it uses less digits than its factorization.

81367792 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1381 (or 1375 counting only the distinct ones).

The product of its digits is 127008, while the sum is 43.

The square root of 81367792 is about 9020.4097467909. The cubic root of 81367792 is about 433.3287562962.

The spelling of 81367792 in words is "eighty-one million, three hundred sixty-seven thousand, seven hundred ninety-two".