28128310853769 has 135 divisors (see below), whose sum is σ = 47982391903719. Its totient is φ = 15877744454880.

The previous prime is 28128310853761. The next prime is 28128310853779. The reversal of 28128310853769 is 96735801382182.

The square root of 28128310853769 is 5303613.

It is a perfect power (a square), and thus also a powerful number.

28128310853769 is a `hidden beast` number, since 2 + 8 + 1 + 2 + 8 + 31 + 0 + 8 + 537 + 69 = 666.

It can be written as a sum of positive squares in only one way, i.e., 19605297717369 + 8523013136400 = 4427787^2 + 2919420^2 .

It is not a de Polignac number, because 28128310853769 - 2³ = 28128310853761 is a prime.

It is a super-2 number, since 2×28128310853769² (a number of 28 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (28128310853761) by changing a digit.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 84979790934 + ... + 84979791264.

Almost surely, 2^{28128310853769} is an apocalyptic number.

28128310853769 is the 5303613-rd square number.

28128310853769 is the 2651807-th centered octagonal number.

It is an amenable number.

28128310853769 is a deficient number, since it is larger than the sum of its proper divisors (19854081049950).

28128310853769 is an frugal number, since it uses more digits than its factorization.

28128310853769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 914 (or 450 counting only the distinct ones).

The product of its (nonzero) digits is 34836480, while the sum is 63.

The spelling of 28128310853769 in words is "twenty-eight trillion, one hundred twenty-eight billion, three hundred ten million, eight hundred fifty-three thousand, seven hundred sixty-nine".