128313891 has 12 divisors (see below), whose sum is σ = 190352032. Its totient is φ = 83230416.

The previous prime is 128313877. The next prime is 128313907. The reversal of 128313891 is 198313821.

It is not a de Polignac number, because 128313891 - 2⁹ = 128313379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128313851) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 192331 + ... + 192996.

Almost surely, 2^128313891 is an apocalyptic number.

128313891 is a deficient number, since it is larger than the sum of its proper divisors (62038141).

128313891 is a wasteful number, since it uses less digits than its factorization.

128313891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 385370 (or 385367 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 128313891 is about 11327.5721582341. The cubic root of 128313891 is about 504.3800397962.

The spelling of 128313891 in words is "one hundred twenty-eight million, three hundred thirteen thousand, eight hundred ninety-one".