28013780 has 12 divisors (see below), whose sum is σ = 58828980. Its totient is φ = 11205504.

The previous prime is 28013767. The next prime is 28013803. The reversal of 28013780 is 8731082.

It can be written as a sum of positive squares in 2 ways, for example, as 7474756 + 20539024 = 2734^2 + 4532^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 700325 + ... + 700364.

It is an arithmetic number, because the mean of its divisors is an integer number (4902415).

Almost surely, 2^28013780 is an apocalyptic number.

28013780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28013780 is an abundant number, since it is smaller than the sum of its proper divisors (30815200).

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

28013780 is a wasteful number, since it uses less digits than its factorization.

28013780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1400698 (or 1400696 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 28013780 is about 5292.8045495748. The cubic root of 28013780 is about 303.7087035369.

The spelling of 28013780 in words is "twenty-eight million, thirteen thousand, seven hundred eighty".