28511380 has 24 divisors (see below), whose sum is σ = 63396648. Its totient is φ = 10733568.

The previous prime is 28511377. The next prime is 28511387. The reversal of 28511380 is 8311582.

It can be written as a sum of positive squares in 4 ways, for example, as 5143824 + 23367556 = 2268^2 + 4834^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28511387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41589 + ... + 42268.

It is an arithmetic number, because the mean of its divisors is an integer number (2641527).

Almost surely, 2^28511380 is an apocalyptic number.

28511380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28511380 is an abundant number, since it is smaller than the sum of its proper divisors (34885268).

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

28511380 is a wasteful number, since it uses less digits than its factorization.

28511380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83883 (or 83881 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 28511380 is about 5339.6048542940. The cubic root of 28511380 is about 305.4963877844.

The spelling of 28511380 in words is "twenty-eight million, five hundred eleven thousand, three hundred eighty".