28539780 has 48 divisors (see below), whose sum is σ = 83389824. Its totient is φ = 7279360.

The previous prime is 28539779. The next prime is 28539781. The reversal of 28539780 is 8793582.

It is an interprime number because it is at equal distance from previous prime (28539779) and next prime (28539781).

It is not an unprimeable number, because it can be changed into a prime (28539781) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8961 + ... + 11720.

It is an arithmetic number, because the mean of its divisors is an integer number (1737288).

Almost surely, 2^28539780 is an apocalyptic number.

28539780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28539780 is an abundant number, since it is smaller than the sum of its proper divisors (54850044).

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

28539780 is a wasteful number, since it uses less digits than its factorization.

28539780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20716 (or 20714 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 42.

The square root of 28539780 is about 5342.2635651941. The cubic root of 28539780 is about 305.5977884447.

The spelling of 28539780 in words is "twenty-eight million, five hundred thirty-nine thousand, seven hundred eighty".