28001520 has 60 divisors (see below), whose sum is σ = 94040856. Its totient is φ = 7466880.

The previous prime is 28001509. The next prime is 28001527. The reversal of 28001520 is 2510082.

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 (18).

It is a junction number, because it is equal to n+sod(n) for n = 28001493 and 28001502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28001527) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18726 + ... + 20165.

Almost surely, 2^28001520 is an apocalyptic number.

28001520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28001520 is an abundant number, since it is smaller than the sum of its proper divisors (66039336).

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

28001520 is a wasteful number, since it uses less digits than its factorization.

28001520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38910 (or 38901 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 28001520 is about 5291.6462466798. The cubic root of 28001520 is about 303.6643918682.

The spelling of 28001520 in words is "twenty-eight million, one thousand, five hundred twenty".