81396772 has 12 divisors (see below), whose sum is σ = 144161136. Its totient is φ = 40207880.

The previous prime is 81396761. The next prime is 81396773. The reversal of 81396772 is 27769318.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (81396773) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122254 + ... + 122917.

It is an arithmetic number, because the mean of its divisors is an integer number (12013428).

Almost surely, 2^81396772 is an apocalyptic number.

It is an amenable number.

81396772 is a deficient number, since it is larger than the sum of its proper divisors (62764364).

81396772 is a wasteful number, since it uses less digits than its factorization.

81396772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245258 (or 245256 counting only the distinct ones).

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

The square root of 81396772 is about 9022.0159609701. The cubic root of 81396772 is about 433.3801950636.

The spelling of 81396772 in words is "eighty-one million, three hundred ninety-six thousand, seven hundred seventy-two".