27996640 has 72 divisors (see below), whose sum is σ = 76962312. Its totient is φ = 9596160.

The previous prime is 27996601. The next prime is 27996643. The reversal of 27996640 is 4669972.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27996643) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6055 + ... + 9625.

It is an arithmetic number, because the mean of its divisors is an integer number (1068921).

Almost surely, 2^27996640 is an apocalyptic number.

27996640 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 27996640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38481156).

27996640 is an abundant number, since it is smaller than the sum of its proper divisors (48965672).

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

27996640 is a wasteful number, since it uses less digits than its factorization.

27996640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3600 (or 3585 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 43.

The square root of 27996640 is about 5291.1851224466. The cubic root of 27996640 is about 303.6467503458.

The spelling of 27996640 in words is "twenty-seven million, nine hundred ninety-six thousand, six hundred forty".