28121712080 has 160 divisors (see below), whose sum is σ = 81594777600. Its totient is φ = 8756789760.

The previous prime is 28121712079. The next prime is 28121712139. The reversal of 28121712080 is 8021712182.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10464497 + ... + 10467183.

It is an arithmetic number, because the mean of its divisors is an integer number (509967360).

Almost surely, 2^28121712080 is an apocalyptic number.

28121712080 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 28121712080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40797388800).

28121712080 is an abundant number, since it is smaller than the sum of its proper divisors (53473065520).

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

28121712080 is a wasteful number, since it uses less digits than its factorization.

28121712080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4417 (or 4411 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 32.

The spelling of 28121712080 in words is "twenty-eight billion, one hundred twenty-one million, seven hundred twelve thousand, eighty".