2016126781 has 8 divisors (see below), whose sum is σ = 2192418360. Its totient is φ = 1846245888.

The previous prime is 2016126773. The next prime is 2016126787. The reversal of 2016126781 is 1876216102.

It can be written as a sum of positive squares in 4 ways, for example, as 626701156 + 1389425625 = 25034^2 + 37275^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2016126781 - 2³ = 2016126773 is a prime.

It is a super-2 number, since 2×2016126781² = 8129534394130843922, 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 (2016126787) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1602016 + ... + 1603273.

It is an arithmetic number, because the mean of its divisors is an integer number (274052295).

Almost surely, 2^2016126781 is an apocalyptic number.

It is an amenable number.

2016126781 is a deficient number, since it is larger than the sum of its proper divisors (176291579).

2016126781 is a wasteful number, since it uses less digits than its factorization.

2016126781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3205343.

The product of its (nonzero) digits is 8064, while the sum is 34.

The square root of 2016126781 is about 44901.3004377379. The cubic root of 2016126781 is about 1263.2984002720.

The spelling of 2016126781 in words is "two billion, sixteen million, one hundred twenty-six thousand, seven hundred eighty-one".