81646793 has 4 divisors (see below), whose sum is σ = 82234320. Its totient is φ = 81059268.

The previous prime is 81646783. The next prime is 81646813. The reversal of 81646793 is 39764618.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81646793 - 2⁶ = 81646729 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81646783) 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, 293555 + ... + 293832.

It is an arithmetic number, because the mean of its divisors is an integer number (20558580).

Almost surely, 2^81646793 is an apocalyptic number.

It is an amenable number.

81646793 is a deficient number, since it is larger than the sum of its proper divisors (587527).

81646793 is a wasteful number, since it uses less digits than its factorization.

81646793 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 587526.

The product of its digits is 217728, while the sum is 44.

The square root of 81646793 is about 9035.8614973892. The cubic root of 81646793 is about 433.8234697972.

The spelling of 81646793 in words is "eighty-one million, six hundred forty-six thousand, seven hundred ninety-three".