81793936 has 135 divisors (see below), whose sum is σ = 206680689. Its totient is φ = 31256064.

The previous prime is 81793931. The next prime is 81793963. The reversal of 81793936 is 63939718.

The square root of 81793936 is 9044.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 63680400 + 18113536 = 7980^2 + 4256^2 .

It is not an unprimeable number, because it can be changed into a prime (81793931) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 4304935 + ... + 4304953.

Almost surely, 2^81793936 is an apocalyptic number.

81793936 is the 9044-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81793936

81793936 is an abundant number, since it is smaller than the sum of its proper divisors (124886753).

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

81793936 is a wasteful number, since it uses less digits than its factorization.

81793936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94 (or 45 counting only the distinct ones).

The product of its digits is 244944, while the sum is 46.

The cubic root of 81793936 is about 434.0839241102.

The spelling of 81793936 in words is "eighty-one million, seven hundred ninety-three thousand, nine hundred thirty-six".