27997440 has 144 divisors (see below), whose sum is σ = 93598848. Its totient is φ = 7118848.

The previous prime is 27997421. The next prime is 27997481. The reversal of 27997440 is 4479972.

It is a junction number, because it is equal to n+sod(n) for n = 27997392 and 27997401.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 88162 + ... + 88478.

It is an arithmetic number, because the mean of its divisors is an integer number (649992).

Almost surely, 2^27997440 is an apocalyptic number.

27997440 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 27997440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46799424).

27997440 is an abundant number, since it is smaller than the sum of its proper divisors (65601408).

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

27997440 is a wasteful number, since it uses less digits than its factorization.

27997440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 364 (or 350 counting only the distinct ones).

The product of its (nonzero) digits is 127008, while the sum is 42.

The square root of 27997440 is about 5291.2607193371. The cubic root of 27997440 is about 303.6496425391.

The spelling of 27997440 in words is "twenty-seven million, nine hundred ninety-seven thousand, four hundred forty".