2211660138681 has 48 divisors (see below), whose sum is σ = 3658129602816. Its totient is φ = 1261338075648.

The previous prime is 2211660138679. The next prime is 2211660138703. The reversal of 2211660138681 is 1868310661122.

2211660138681 is a `hidden beast` number, since 2 + 2 + 1 + 1 + 6 + 601 + 38 + 6 + 8 + 1 = 666.

It is not a de Polignac number, because 2211660138681 - 2¹ = 2211660138679 is a prime.

It is a super-2 number, since 2×2211660138681² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2211660134681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 82042701 + ... + 82069653.

It is an arithmetic number, because the mean of its divisors is an integer number (76211033392).

Almost surely, 2^{2211660138681} is an apocalyptic number.

2211660138681 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2211660138681 is a deficient number, since it is larger than the sum of its proper divisors (1446469464135).

2211660138681 is a wasteful number, since it uses less digits than its factorization.

2211660138681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29462 (or 29459 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

The spelling of 2211660138681 in words is "two trillion, two hundred eleven billion, six hundred sixty million, one hundred thirty-eight thousand, six hundred eighty-one".