27721440 has 288 divisors, whose sum is σ = 105670656. Its totient is φ = 6842880.

The previous prime is 27721427. The next prime is 27721457. The reversal of 27721440 is 4412772.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 894225 + ... + 894255.

It is an arithmetic number, because the mean of its divisors is an integer number (366912).

Almost surely, 2^27721440 is an apocalyptic number.

27721440 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 27721440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52835328).

27721440 is an abundant number, since it is smaller than the sum of its proper divisors (77949216).

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

27721440 is a wasteful number, since it uses less digits than its factorization.

27721440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84 (or 64 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 27.

The square root of 27721440 is about 5265.1153833511. The cubic root of 27721440 is about 302.6485484916.

The spelling of 27721440 in words is "twenty-seven million, seven hundred twenty-one thousand, four hundred forty".