2136683781 has 12 divisors (see below), whose sum is σ = 3088732140. Its totient is φ = 1423343040.

The previous prime is 2136683771. The next prime is 2136683797. The reversal of 2136683781 is 1873866312.

2136683781 is a `hidden beast` number, since 213 + 6 + 68 + 378 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1586030625 + 550653156 = 39825^2 + 23466^2 .

It is not a de Polignac number, because 2136683781 - 2¹¹ = 2136681733 is a prime.

It is a super-2 number, since 2×2136683781² = 9130835159976911922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2136683701) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 80490 + ... + 103691.

It is an arithmetic number, because the mean of its divisors is an integer number (257394345).

Almost surely, 2^2136683781 is an apocalyptic number.

It is an amenable number.

2136683781 is a deficient number, since it is larger than the sum of its proper divisors (952048359).

2136683781 is a wasteful number, since it uses less digits than its factorization.

2136683781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185476 (or 185473 counting only the distinct ones).

The product of its digits is 290304, while the sum is 45.

The square root of 2136683781 is about 46224.2769656811. The cubic root of 2136683781 is about 1287.9927481572.

It can be divided in two parts, 213668 and 3781, that multiplied together give a palindrome (807878708).

The spelling of 2136683781 in words is "two billion, one hundred thirty-six million, six hundred eighty-three thousand, seven hundred eighty-one".