28147540 has 24 divisors (see below), whose sum is σ = 59231592. Its totient is φ = 11235840.

The previous prime is 28147523. The next prime is 28147547. The reversal of 28147540 is 4574182.

It can be written as a sum of positive squares in 4 ways, for example, as 121104 + 28026436 = 348^2 + 5294^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28147547) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11200 + ... + 13480.

It is an arithmetic number, because the mean of its divisors is an integer number (2467983).

Almost surely, 2^28147540 is an apocalyptic number.

28147540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28147540 is an abundant number, since it is smaller than the sum of its proper divisors (31084052).

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

28147540 is a wasteful number, since it uses less digits than its factorization.

28147540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2907 (or 2905 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 31.

The square root of 28147540 is about 5305.4255248755. The cubic root of 28147540 is about 304.1913182831.

The spelling of 28147540 in words is "twenty-eight million, one hundred forty-seven thousand, five hundred forty".