799781 has 4 divisors (see below), whose sum is σ = 804000. Its totient is φ = 795564.

The previous prime is 799759. The next prime is 799789. The reversal of 799781 is 187997.

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, and also an emirpimes, since its reverse is a distinct semiprime: 187997 = 37 ⋅5081.

It is a cyclic number.

It is not a de Polignac number, because 799781 - 2¹⁰ = 798757 is a prime.

It is a super-2 number, since 2×799781² = 1279299295922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (799789) 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, 1811 + ... + 2208.

It is an arithmetic number, because the mean of its divisors is an integer number (201000).

2⁷⁹⁹⁷⁸¹ is an apocalyptic number.

It is an amenable number.

799781 is a deficient number, since it is larger than the sum of its proper divisors (4219).

799781 is a wasteful number, since it uses less digits than its factorization.

799781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4218.

The product of its digits is 31752, while the sum is 41.

The square root of 799781 is about 894.3047578986. The cubic root of 799781 is about 92.8233049995.

The spelling of 799781 in words is "seven hundred ninety-nine thousand, seven hundred eighty-one".