2781636381 has 12 divisors (see below), whose sum is σ = 4018522560. Its totient is φ = 1854145800.

The previous prime is 2781636371. The next prime is 2781636397. The reversal of 2781636381 is 1836361872.

2781636381 is a `hidden beast` number, since 2 + 7 + 8 + 1 + 6 + 3 + 638 + 1 = 666.

It is not a de Polignac number, because 2781636381 - 2⁶ = 2781636317 is a prime.

It is a super-2 number, since 2×2781636381² = 15475001912205554322, which contains 22 as substring.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2781636301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 53356 + ... + 91706.

It is an arithmetic number, because the mean of its divisors is an integer number (334876880).

Almost surely, 2^2781636381 is an apocalyptic number.

It is an amenable number.

2781636381 is a deficient number, since it is larger than the sum of its proper divisors (1236886179).

2781636381 is a wasteful number, since it uses less digits than its factorization.

2781636381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46416 (or 46413 counting only the distinct ones).

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

The square root of 2781636381 is about 52741.2208903055. The cubic root of 2781636381 is about 1406.3717020834.

The spelling of 2781636381 in words is "two billion, seven hundred eighty-one million, six hundred thirty-six thousand, three hundred eighty-one".