128311881 has 8 divisors (see below), whose sum is σ = 173426400. Its totient is φ = 84369312.

The previous prime is 128311877. The next prime is 128311907. The reversal of 128311881 is 188113821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 128311881 - 2² = 128311877 is a prime.

It is a super-2 number, since 2×128311881² = 32927877611516322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (128311681) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 292731 + ... + 293168.

It is an arithmetic number, because the mean of its divisors is an integer number (21678300).

Almost surely, 2^128311881 is an apocalyptic number.

It is an amenable number.

128311881 is a deficient number, since it is larger than the sum of its proper divisors (45114519).

128311881 is an equidigital number, since it uses as much as digits as its factorization.

128311881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 585975.

The product of its digits is 3072, while the sum is 33.

The square root of 128311881 is about 11327.4834363154. The cubic root of 128311881 is about 504.3774061266.

The spelling of 128311881 in words is "one hundred twenty-eight million, three hundred eleven thousand, eight hundred eighty-one".