27993645 has 96 divisors (see below), whose sum is σ = 56339712. Its totient is φ = 12773376.

The previous prime is 27993643. The next prime is 27993677. The reversal of 27993645 is 54639972.

It is a happy number.

It is not a de Polignac number, because 27993645 - 2¹ = 27993643 is a prime.

It is a super-3 number, since 3×27993645³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 27993645.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27993643) 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 95 ways as a sum of consecutive naturals, for example, 650994 + ... + 651036.

It is an arithmetic number, because the mean of its divisors is an integer number (586872).

It is a vampire number, since it can be written as 2967 ⋅ 9435 (with its own digits).

Almost surely, 2^27993645 is an apocalyptic number.

It is an amenable number.

27993645 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

27993645 is a wasteful number, since it uses less digits than its factorization.

27993645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131 (or 128 counting only the distinct ones).

The product of its digits is 408240, while the sum is 45.

The square root of 27993645 is about 5290.9020969963. The cubic root of 27993645 is about 303.6359222077.

The spelling of 27993645 in words is "twenty-seven million, nine hundred ninety-three thousand, six hundred forty-five".