27991040 has 176 divisors, whose sum is σ = 84893184. Its totient is φ = 8601600.

The previous prime is 27991031. The next prime is 27991057. The reversal of 27991040 is 4019972.

It is a tau number, because it is divible by the number of its divisors (176).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 27990988 and 27991006.

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, 394205 + ... + 394275.

Almost surely, 2^27991040 is an apocalyptic number.

27991040 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 27991040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42446592).

27991040 is an abundant number, since it is smaller than the sum of its proper divisors (56902144).

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

27991040 is a wasteful number, since it uses less digits than its factorization.

27991040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114 (or 96 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 27991040 is about 5290.6559139676. The cubic root of 27991040 is about 303.6265034496.

It can be divided in two parts, 279 and 91040, that added together give a palindrome (91319).

The spelling of 27991040 in words is "twenty-seven million, nine hundred ninety-one thousand, forty".