28512403920 has 640 divisors, whose sum is σ = 131871559680. Its totient is φ = 5468497920.

The previous prime is 28512403891. The next prime is 28512403957. The reversal of 28512403920 is 2930421582.

It is a happy number.

28512403920 is a `hidden beast` number, since 28 + 5 + 1 + 240 + 392 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2155567 + ... + 2168753.

It is an arithmetic number, because the mean of its divisors is an integer number (206049312).

Almost surely, 2^28512403920 is an apocalyptic number.

28512403920 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 28512403920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (65935779840).

28512403920 is an abundant number, since it is smaller than the sum of its proper divisors (103359155760).

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

28512403920 is a wasteful number, since it uses less digits than its factorization.

28512403920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13240 (or 13228 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The spelling of 28512403920 in words is "twenty-eight billion, five hundred twelve million, four hundred three thousand, nine hundred twenty".