28185709440 has 512 divisors, whose sum is σ = 105910272000. Its totient is φ = 6372753408.

The previous prime is 28185709417. The next prime is 28185709481. The reversal of 28185709440 is 4490758182.

It is a happy number.

It is a super-2 number, since 2×28185709440² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 28185709440.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 83636952 + ... + 83637288.

It is an arithmetic number, because the mean of its divisors is an integer number (206856000).

Almost surely, 2^28185709440 is an apocalyptic number.

28185709440 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 28185709440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52955136000).

28185709440 is an abundant number, since it is smaller than the sum of its proper divisors (77724562560).

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

28185709440 is a wasteful number, since it uses less digits than its factorization.

28185709440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 507 (or 481 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 48.

The spelling of 28185709440 in words is "twenty-eight billion, one hundred eighty-five million, seven hundred nine thousand, four hundred forty".