28161559440 has 480 divisors, whose sum is σ = 117734964480. Its totient is φ = 6039982080.

The previous prime is 28161559429. The next prime is 28161559469. The reversal of 28161559440 is 4495516182.

28161559440 is a `hidden beast` number, since 2 + 8 + 1 + 6 + 15 + 594 + 40 = 666.

It is a super-2 number, since 2×28161559440² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 85080075 + ... + 85080405.

It is an arithmetic number, because the mean of its divisors is an integer number (245281176).

Almost surely, 2^28161559440 is an apocalyptic number.

28161559440 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 28161559440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (58867482240).

28161559440 is an abundant number, since it is smaller than the sum of its proper divisors (89573405040).

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

28161559440 is a wasteful number, since it uses less digits than its factorization.

28161559440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 708 (or 365 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 45.

The spelling of 28161559440 in words is "twenty-eight billion, one hundred sixty-one million, five hundred fifty-nine thousand, four hundred forty".