28125540 has 36 divisors (see below), whose sum is σ = 85314684. Its totient is φ = 7500096.

The previous prime is 28125533. The next prime is 28125541. The reversal of 28125540 is 4552182.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 2965284 + 25160256 = 1722^2 + 5016^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (28125541) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 77947 + ... + 78306.

Almost surely, 2^28125540 is an apocalyptic number.

28125540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28125540 is an abundant number, since it is smaller than the sum of its proper divisors (57189144).

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

28125540 is a wasteful number, since it uses less digits than its factorization.

28125540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156268 (or 156263 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 27.

The square root of 28125540 is about 5303.3517703430. The cubic root of 28125540 is about 304.1120460709.

The spelling of 28125540 in words is "twenty-eight million, one hundred twenty-five thousand, five hundred forty".