81740773 has 4 divisors (see below), whose sum is σ = 81821088. Its totient is φ = 81660460.

The previous prime is 81740759. The next prime is 81740779. The reversal of 81740773 is 37704718.

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 81740773 - 2⁵ = 81740741 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81740779) 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, 38611 + ... + 40672.

It is an arithmetic number, because the mean of its divisors is an integer number (20455272).

Almost surely, 2^81740773 is an apocalyptic number.

It is an amenable number.

81740773 is a deficient number, since it is larger than the sum of its proper divisors (80315).

81740773 is a wasteful number, since it uses less digits than its factorization.

81740773 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80314.

The product of its (nonzero) digits is 32928, while the sum is 37.

The square root of 81740773 is about 9041.0603913479. The cubic root of 81740773 is about 433.9898576208.

The spelling of 81740773 in words is "eighty-one million, seven hundred forty thousand, seven hundred seventy-three".