28558640 has 160 divisors (see below), whose sum is σ = 80994816. Its totient is φ = 9236480.

The previous prime is 28558637. The next prime is 28558661. The reversal of 28558640 is 4685582.

It is a junction number, because it is equal to n+sod(n) for n = 28558594 and 28558603.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 344039 + ... + 344121.

Almost surely, 2^28558640 is an apocalyptic number.

28558640 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 28558640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40497408).

28558640 is an abundant number, since it is smaller than the sum of its proper divisors (52436176).

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

28558640 is a wasteful number, since it uses less digits than its factorization.

28558640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 76800, while the sum is 38.

The square root of 28558640 is about 5344.0284430381. The cubic root of 28558640 is about 305.6650898881.

The spelling of 28558640 in words is "twenty-eight million, five hundred fifty-eight thousand, six hundred forty".