27658640 has 20 divisors (see below), whose sum is σ = 64306524. Its totient is φ = 11063424.

The previous prime is 27658613. The next prime is 27658649. The reversal of 27658640 is 4685672.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 4194304 + 23464336 = 2048^2 + 4844^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 27658594 and 27658603.

It is not an unprimeable number, because it can be changed into a prime (27658649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 172787 + ... + 172946.

Almost surely, 2^27658640 is an apocalyptic number.

27658640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

27658640 is an abundant number, since it is smaller than the sum of its proper divisors (36647884).

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

27658640 is a wasteful number, since it uses less digits than its factorization.

27658640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345746 (or 345740 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 38.

The square root of 27658640 is about 5259.1482200067. The cubic root of 27658640 is about 302.4198362360.

The spelling of 27658640 in words is "twenty-seven million, six hundred fifty-eight thousand, six hundred forty".