28447920 has 60 divisors (see below), whose sum is σ = 95540016. Its totient is φ = 7585920.

The previous prime is 28447907. The next prime is 28447957. The reversal of 28447920 is 2974482.

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19036 + ... + 20475.

Almost surely, 2^28447920 is an apocalyptic number.

28447920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28447920 is an abundant number, since it is smaller than the sum of its proper divisors (67092096).

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

28447920 is a wasteful number, since it uses less digits than its factorization.

28447920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39530 (or 39521 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 28447920 is about 5333.6591567141. The cubic root of 28447920 is about 305.2695637098.

The spelling of 28447920 in words is "twenty-eight million, four hundred forty-seven thousand, nine hundred twenty".