128881248561 has 72 divisors (see below), whose sum is σ = 207843574848. Its totient is φ = 76499121600.

The previous prime is 128881248539. The next prime is 128881248583. The reversal of 128881248561 is 165842188821.

128881248561 is a `hidden beast` number, since 1 + 2 + 88 + 81 + 2 + 485 + 6 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (128881248539) and next prime (128881248583).

It is not a de Polignac number, because 128881248561 - 2¹⁸ = 128880986417 is a prime.

It is a super-2 number, since 2×128881248561² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 128881248498 and 128881248507.

It is not an unprimeable number, because it can be changed into a prime (128881248961) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 37214916 + ... + 37218378.

Almost surely, 2^128881248561 is an apocalyptic number.

It is an amenable number.

128881248561 is a deficient number, since it is larger than the sum of its proper divisors (78962326287).

128881248561 is a wasteful number, since it uses less digits than its factorization.

128881248561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3875 (or 3841 counting only the distinct ones).

The product of its digits is 1966080, while the sum is 54.

The spelling of 128881248561 in words is "one hundred twenty-eight billion, eight hundred eighty-one million, two hundred forty-eight thousand, five hundred sixty-one".