28243765447920 has 560 divisors, whose sum is σ = 111109269132000. Its totient is φ = 6610866554880.

The previous prime is 28243765447913. The next prime is 28243765448021. The reversal of 28243765447920 is 2974456734282.

28243765447920 is a `hidden beast` number, since 2 + 8 + 2 + 43 + 7 + 65 + 447 + 92 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 17845006 + ... + 19363154.

Almost surely, 2^{28243765447920} is an apocalyptic number.

28243765447920 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 28243765447920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (55554634566000).

28243765447920 is an abundant number, since it is smaller than the sum of its proper divisors (82865503684080).

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

28243765447920 is a wasteful number, since it uses less digits than its factorization.

28243765447920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1518220 (or 1518199 counting only the distinct ones).

The product of its (nonzero) digits is 162570240, while the sum is 63.

The spelling of 28243765447920 in words is "twenty-eight trillion, two hundred forty-three billion, seven hundred sixty-five million, four hundred forty-seven thousand, nine hundred twenty".