27989780 has 90 divisors (see below), whose sum is σ = 74072754. Its totient is φ = 8858304.

The previous prime is 27989771. The next prime is 27989821. The reversal of 27989780 is 8798972.

It is a happy number.

27989780 is nontrivially palindromic in base 9.

It can be written as a sum of positive squares in 5 ways, for example, as 25120144 + 2869636 = 5012^2 + 1694^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 2153054 + ... + 2153066.

Almost surely, 2^27989780 is an apocalyptic number.

27989780 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 27989780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37036377).

27989780 is an abundant number, since it is smaller than the sum of its proper divisors (46082974).

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

27989780 is an equidigital number, since it uses as much as digits as its factorization.

27989780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75 (or 27 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 50.

The square root of 27989780 is about 5290.5368347645. The cubic root of 27989780 is about 303.6219475258.

The spelling of 27989780 in words is "twenty-seven million, nine hundred eighty-nine thousand, seven hundred eighty".