27996840 has 80 divisors (see below), whose sum is σ = 94111380. Its totient is φ = 7464960.

The previous prime is 27996817. The next prime is 27996847. The reversal of 27996840 is 4869972.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 24147396 + 3849444 = 4914^2 + 1962^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27996847) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1081 + ... + 7560.

Almost surely, 2^27996840 is an apocalyptic number.

27996840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 27996840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47055690).

27996840 is an abundant number, since it is smaller than the sum of its proper divisors (66114540).

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

27996840 is a wasteful number, since it uses less digits than its factorization.

27996840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8664 (or 8651 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 27996840 is about 5291.2040217705. The cubic root of 27996840 is about 303.6474733993.

The spelling of 27996840 in words is "twenty-seven million, nine hundred ninety-six thousand, eight hundred forty".