28957640 has 64 divisors (see below), whose sum is σ = 67772160. Its totient is φ = 11128320.

The previous prime is 28957639. The next prime is 28957657. The reversal of 28957640 is 4675982.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 137135 + ... + 137345.

It is an arithmetic number, because the mean of its divisors is an integer number (1058940).

Almost surely, 2^28957640 is an apocalyptic number.

28957640 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 28957640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33886080).

28957640 is an abundant number, since it is smaller than the sum of its proper divisors (38814520).

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

28957640 is a wasteful number, since it uses less digits than its factorization.

28957640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 342 (or 338 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 41.

The square root of 28957640 is about 5381.2303425890. The cubic root of 28957640 is about 307.0820196277.

The spelling of 28957640 in words is "twenty-eight million, nine hundred fifty-seven thousand, six hundred forty".