28975440 has 160 divisors (see below), whose sum is σ = 99743616. Its totient is φ = 6912000.

The previous prime is 28975439. The next prime is 28975459. The reversal of 28975440 is 4457982.

It is a super-2 number, since 2×28975440² = 1679152246387200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

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, 115315 + ... + 115565.

Almost surely, 2^28975440 is an apocalyptic number.

28975440 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 28975440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49871808).

28975440 is an abundant number, since it is smaller than the sum of its proper divisors (70768176).

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

28975440 is a wasteful number, since it uses less digits than its factorization.

28975440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317 (or 311 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 39.

The square root of 28975440 is about 5382.8839853744. The cubic root of 28975440 is about 307.1449269221.

The spelling of 28975440 in words is "twenty-eight million, nine hundred seventy-five thousand, four hundred forty".