3116781 has 6 divisors (see below), whose sum is σ = 4502030. Its totient is φ = 2077848.

The previous prime is 3116777. The next prime is 3116783. The reversal of 3116781 is 1876113.

It can be written as a sum of positive squares in only one way, i.e., 2673225 + 443556 = 1635^2 + 666^2 .

It is not a de Polignac number, because 3116781 - 2² = 3116777 is a prime.

It is a super-2 number, since 2×3116781² = 19428647603922, which contains 22 as substring.

It is a Duffinian number.

3116781 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3116783) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 173146 + ... + 173163.

Almost surely, 2^3116781 is an apocalyptic number.

It is an amenable number.

3116781 is a deficient number, since it is larger than the sum of its proper divisors (1385249).

3116781 is a wasteful number, since it uses less digits than its factorization.

3116781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 346315 (or 346312 counting only the distinct ones).

The product of its digits is 1008, while the sum is 27.

The square root of 3116781 is about 1765.4407381728. The cubic root of 3116781 is about 146.0726010346.

The spelling of 3116781 in words is "three million, one hundred sixteen thousand, seven hundred eighty-one".