781013 has 4 divisors (see below), whose sum is σ = 783180. Its totient is φ = 778848.

The previous prime is 781007. The next prime is 781021. The reversal of 781013 is 310187.

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

It can be written as a sum of positive squares in 2 ways, for example, as 418609 + 362404 = 647^2 + 602^2 .

It is a cyclic number.

It is not a de Polignac number, because 781013 - 2¹⁴ = 764629 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 (781003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 398 + ... + 1311.

It is an arithmetic number, because the mean of its divisors is an integer number (195795).

2⁷⁸¹⁰¹³ is an apocalyptic number.

It is an amenable number.

781013 is a deficient number, since it is larger than the sum of its proper divisors (2167).

781013 is a wasteful number, since it uses less digits than its factorization.

781013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2166.

The product of its (nonzero) digits is 168, while the sum is 20.

The square root of 781013 is about 883.7493988683. The cubic root of 781013 is about 92.0914732925.

The spelling of 781013 in words is "seven hundred eighty-one thousand, thirteen".