27963981 has 16 divisors (see below), whose sum is σ = 41588800. Its totient is φ = 18570384.

The previous prime is 27963973. The next prime is 27964039. The reversal of 27963981 is 18936972.

27963981 is a `hidden beast` number, since 2 + 7 + 9 + 639 + 8 + 1 = 666.

27963981 is a nontrivial binomial coefficient, being equal to C(7479, 2).

It is not a de Polignac number, because 27963981 - 2³ = 27963973 is a prime.

It is a super-2 number, since 2×27963981² = 1563968466736722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27963911) 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 15 ways as a sum of consecutive naturals, for example, 5610 + ... + 9348.

It is an arithmetic number, because the mean of its divisors is an integer number (2599300).

Almost surely, 2^27963981 is an apocalyptic number.

27963981 is the 7478-th triangular number.

It is an amenable number.

27963981 is a deficient number, since it is larger than the sum of its proper divisors (13624819).

27963981 is a wasteful number, since it uses less digits than its factorization.

27963981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4025 (or 4019 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 27963981 is about 5288.0980512846. The cubic root of 27963981 is about 303.5286331025.

The spelling of 27963981 in words is "twenty-seven million, nine hundred sixty-three thousand, nine hundred eighty-one".