27957681 has 24 divisors (see below), whose sum is σ = 42207360. Its totient is φ = 17814816.

The previous prime is 27957667. The next prime is 27957701. The reversal of 27957681 is 18675972.

Added to its reverse (18675972) it gives a triangular number (46633653 = T₉₆₅₇).

27957681 is a `hidden beast` number, since 2 + 79 + 576 + 8 + 1 = 666.

It is not a de Polignac number, because 27957681 - 2²¹ = 25860529 is a prime.

It is a super-2 number, since 2×27957681² = 1563263853795522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (27957781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18936 + ... + 20358.

It is an arithmetic number, because the mean of its divisors is an integer number (1758640).

Almost surely, 2^27957681 is an apocalyptic number.

It is an amenable number.

27957681 is a deficient number, since it is larger than the sum of its proper divisors (14249679).

27957681 is a wasteful number, since it uses less digits than its factorization.

27957681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1525 (or 1522 counting only the distinct ones).

The product of its digits is 211680, while the sum is 45.

The square root of 27957681 is about 5287.5023404250. The cubic root of 27957681 is about 303.5058374211.

Adding to 27957681 its reverse (18675972), we get a triangular number (46633653 = T₉₆₅₇).

The spelling of 27957681 in words is "twenty-seven million, nine hundred fifty-seven thousand, six hundred eighty-one".