28157860 has 12 divisors (see below), whose sum is σ = 59131548. Its totient is φ = 11263136.

The previous prime is 28157821. The next prime is 28157863. The reversal of 28157860 is 6875182.

It can be written as a sum of positive squares in 2 ways, for example, as 11249316 + 16908544 = 3354^2 + 4112^2 .

It is not an unprimeable number, because it can be changed into a prime (28157863) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 703927 + ... + 703966.

It is an arithmetic number, because the mean of its divisors is an integer number (4927629).

Almost surely, 2^28157860 is an apocalyptic number.

28157860 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28157860 is an abundant number, since it is smaller than the sum of its proper divisors (30973688).

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

28157860 is a wasteful number, since it uses less digits than its factorization.

28157860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1407902 (or 1407900 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 37.

The square root of 28157860 is about 5306.3980250260. The cubic root of 28157860 is about 304.2284899249.

The spelling of 28157860 in words is "twenty-eight million, one hundred fifty-seven thousand, eight hundred sixty".