28530640 has 40 divisors (see below), whose sum is σ = 67281408. Its totient is φ = 11249280.

The previous prime is 28530637. The next prime is 28530659. The reversal of 28530640 is 4603582.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 28530599 and 28530608.

It is a congruent number.

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, 3169 + ... + 8191.

Almost surely, 2^28530640 is an apocalyptic number.

28530640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28530640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33640704).

28530640 is an abundant number, since it is smaller than the sum of its proper divisors (38750768).

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

28530640 is a wasteful number, since it uses less digits than its factorization.

28530640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5107 (or 5101 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 28530640 is about 5341.4080540621. The cubic root of 28530640 is about 305.5651619141.

The spelling of 28530640 in words is "twenty-eight million, five hundred thirty thousand, six hundred forty".