231289128 has 256 divisors, whose sum is σ = 790272000. Its totient is φ = 61212672.

The previous prime is 231289117. The next prime is 231289129. The reversal of 231289128 is 821982132.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 231289092 and 231289101.

It is not an unprimeable number, because it can be changed into a prime (231289129) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2384376 + ... + 2384472.

It is an arithmetic number, because the mean of its divisors is an integer number (3087000).

Almost surely, 2^231289128 is an apocalyptic number.

231289128 is a gapful number since it is divisible by the number (28) 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 231289128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (395136000).

231289128 is an abundant number, since it is smaller than the sum of its proper divisors (558982872).

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

231289128 is a wasteful number, since it uses less digits than its factorization.

231289128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221 (or 211 counting only the distinct ones).

The product of its digits is 13824, while the sum is 36.

The square root of 231289128 is about 15208.1927920447. The cubic root of 231289128 is about 613.8351299351.

The spelling of 231289128 in words is "two hundred thirty-one million, two hundred eighty-nine thousand, one hundred twenty-eight".