28481440 has 48 divisors (see below), whose sum is σ = 72468648. Its totient is φ = 10515456.

The previous prime is 28481407. The next prime is 28481459. The reversal of 28481440 is 4418482.

It can be written as a sum of positive squares in 4 ways, for example, as 26255376 + 2226064 = 5124^2 + 1492^2 .

It is a super-2 number, since 2×28481440² = 1622384848947200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4767 + ... + 8926.

Almost surely, 2^28481440 is an apocalyptic number.

28481440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28481440 is an abundant number, since it is smaller than the sum of its proper divisors (43987208).

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

28481440 is a wasteful number, since it uses less digits than its factorization.

28481440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13721 (or 13713 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 31.

The square root of 28481440 is about 5336.8005396492. The cubic root of 28481440 is about 305.3894156988.

The spelling of 28481440 in words is "twenty-eight million, four hundred eighty-one thousand, four hundred forty".