27643640 has 32 divisors (see below), whose sum is σ = 63056880. Its totient is φ = 10904832.

The previous prime is 27643639. The next prime is 27643657. The reversal of 27643640 is 4634672.

It is a junction number, because it is equal to n+sod(n) for n = 27643597 and 27643606.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1814 + ... + 7653.

Almost surely, 2^27643640 is an apocalyptic number.

27643640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

27643640 is an abundant number, since it is smaller than the sum of its proper divisors (35413240).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

27643640 is a wasteful number, since it uses less digits than its factorization.

27643640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9551 (or 9547 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 32.

The square root of 27643640 is about 5257.7219401562. The cubic root of 27643640 is about 302.3651563019.

The spelling of 27643640 in words is "twenty-seven million, six hundred forty-three thousand, six hundred forty".