81793747 has 4 divisors (see below), whose sum is σ = 93478576. Its totient is φ = 70108920.

The previous prime is 81793721. The next prime is 81793769. The reversal of 81793747 is 74739718.

It is a semiprime because it is the product of two primes.

It is a de Polignac number, because none of the positive numbers 2^k-81793747 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81793697 and 81793706.

It is not an unprimeable number, because it can be changed into a prime (81793447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5842404 + ... + 5842417.

It is an arithmetic number, because the mean of its divisors is an integer number (23369644).

Almost surely, 2^81793747 is an apocalyptic number.

81793747 is a deficient number, since it is larger than the sum of its proper divisors (11684829).

81793747 is a wasteful number, since it uses less digits than its factorization.

81793747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11684828.

The product of its digits is 296352, while the sum is 46.

The square root of 81793747 is about 9043.9895510776. The cubic root of 81793747 is about 434.0835897662.

The spelling of 81793747 in words is "eighty-one million, seven hundred ninety-three thousand, seven hundred forty-seven".