28072540 has 12 divisors (see below), whose sum is σ = 58952376. Its totient is φ = 11229008.

The previous prime is 28072523. The next prime is 28072549. The reversal of 28072540 is 4527082.

It is a junction number, because it is equal to n+sod(n) for n = 28072499 and 28072508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28072549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 701794 + ... + 701833.

It is an arithmetic number, because the mean of its divisors is an integer number (4912698).

Almost surely, 2^28072540 is an apocalyptic number.

28072540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28072540 is an abundant number, since it is smaller than the sum of its proper divisors (30879836).

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

28072540 is a wasteful number, since it uses less digits than its factorization.

28072540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1403636 (or 1403634 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 28.

The square root of 28072540 is about 5298.3525741498. The cubic root of 28072540 is about 303.9209022053.

The spelling of 28072540 in words is "twenty-eight million, seventy-two thousand, five hundred forty".