27365661981 has 48 divisors (see below), whose sum is σ = 47669814400. Its totient is φ = 14778008064.

The previous prime is 27365661977. The next prime is 27365662003. The reversal of 27365661981 is 18916656372.

27365661981 is a `hidden beast` number, since 2 + 73 + 6 + 566 + 1 + 9 + 8 + 1 = 666.

It is not a de Polignac number, because 27365661981 - 2² = 27365661977 is a prime.

It is a super-2 number, since 2×27365661981² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27365665981) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 461625 + ... + 517521.

Almost surely, 2^27365661981 is an apocalyptic number.

27365661981 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

27365661981 is a deficient number, since it is larger than the sum of its proper divisors (20304152419).

27365661981 is a wasteful number, since it uses less digits than its factorization.

27365661981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56338 (or 56335 counting only the distinct ones).

The product of its digits is 3265920, while the sum is 54.

The spelling of 27365661981 in words is "twenty-seven billion, three hundred sixty-five million, six hundred sixty-one thousand, nine hundred eighty-one".