27790640 has 40 divisors (see below), whose sum is σ = 65226480. Its totient is φ = 11010816.

The previous prime is 27790621. The next prime is 27790643. The reversal of 27790640 is 4609772.

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 27790640.

It is not an unprimeable number, because it can be changed into a prime (27790643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7127 + ... + 10313.

It is an arithmetic number, because the mean of its divisors is an integer number (1630662).

Almost surely, 2^27790640 is an apocalyptic number.

27790640 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 27790640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32613240).

27790640 is an abundant number, since it is smaller than the sum of its proper divisors (37435840).

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

27790640 is a wasteful number, since it uses less digits than its factorization.

27790640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3309 (or 3303 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 35.

The square root of 27790640 is about 5271.6828432674. The cubic root of 27790640 is about 302.9001693434.

The spelling of 27790640 in words is "twenty-seven million, seven hundred ninety thousand, six hundred forty".