27911138661 has 24 divisors (see below), whose sum is σ = 46106424000. Its totient is φ = 15938528256.

The previous prime is 27911138623. The next prime is 27911138677. The reversal of 27911138661 is 16683111972.

It is not a de Polignac number, because 27911138661 - 2⁶ = 27911138597 is a prime.

It is a super-2 number, since 2×27911138661² (a number of 22 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27911138261) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 53340 + ... + 242213.

It is an arithmetic number, because the mean of its divisors is an integer number (1921101000).

Almost surely, 2^27911138661 is an apocalyptic number.

27911138661 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

27911138661 is a deficient number, since it is larger than the sum of its proper divisors (18195285339).

27911138661 is a wasteful number, since it uses less digits than its factorization.

27911138661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297065 (or 297062 counting only the distinct ones).

The product of its digits is 108864, while the sum is 45.

The spelling of 27911138661 in words is "twenty-seven billion, nine hundred eleven million, one hundred thirty-eight thousand, six hundred sixty-one".