81797732 has 6 divisors (see below), whose sum is σ = 143146038. Its totient is φ = 40898864.

The previous prime is 81797731. The next prime is 81797797. The reversal of 81797732 is 23779718.

It can be written as a sum of positive squares in only one way, i.e., 48804196 + 32993536 = 6986^2 + 5744^2 .

It is not an unprimeable number, because it can be changed into a prime (81797731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10224713 + ... + 10224720.

It is an arithmetic number, because the mean of its divisors is an integer number (23857673).

Almost surely, 2^81797732 is an apocalyptic number.

It is an amenable number.

81797732 is a deficient number, since it is larger than the sum of its proper divisors (61348306).

81797732 is a wasteful number, since it uses less digits than its factorization.

81797732 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20449437 (or 20449435 counting only the distinct ones).

The product of its digits is 148176, while the sum is 44.

The square root of 81797732 is about 9044.2098604577. The cubic root of 81797732 is about 434.0906391845.

The spelling of 81797732 in words is "eighty-one million, seven hundred ninety-seven thousand, seven hundred thirty-two".