781061 has 4 divisors (see below), whose sum is σ = 795852. Its totient is φ = 766272.

The previous prime is 781051. The next prime is 781063. The reversal of 781061 is 160187.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 160187 = 41 ⋅3907.

It can be written as a sum of positive squares in 2 ways, for example, as 616225 + 164836 = 785^2 + 406^2 .

It is a cyclic number.

It is not a de Polignac number, because 781061 - 2¹⁰ = 780037 is a prime.

It is a super-2 number, since 2×781061² = 1220112571442, 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 (781063) 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, 7316 + ... + 7421.

It is an arithmetic number, because the mean of its divisors is an integer number (198963).

2⁷⁸¹⁰⁶¹ is an apocalyptic number.

It is an amenable number.

781061 is a deficient number, since it is larger than the sum of its proper divisors (14791).

781061 is a wasteful number, since it uses less digits than its factorization.

781061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14790.

The product of its (nonzero) digits is 336, while the sum is 23.

The square root of 781061 is about 883.7765554709. The cubic root of 781061 is about 92.0933598595.

The spelling of 781061 in words is "seven hundred eighty-one thousand, sixty-one".