128958831 has 16 divisors (see below), whose sum is σ = 191893600. Its totient is φ = 85593024.

The previous prime is 128958829. The next prime is 128958839. The reversal of 128958831 is 138859821.

It is a happy number.

It is not a de Polignac number, because 128958831 - 2¹ = 128958829 is a prime.

It is a super-2 number, since 2×128958831² = 33260760185773122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128958839) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4246 + ... + 16611.

It is an arithmetic number, because the mean of its divisors is an integer number (11993350).

Almost surely, 2^128958831 is an apocalyptic number.

128958831 is a deficient number, since it is larger than the sum of its proper divisors (62934769).

128958831 is a wasteful number, since it uses less digits than its factorization.

128958831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21095 (or 21089 counting only the distinct ones).

The product of its digits is 138240, while the sum is 45.

The square root of 128958831 is about 11356.0041828101. The cubic root of 128958831 is about 505.2236776666.

The spelling of 128958831 in words is "one hundred twenty-eight million, nine hundred fifty-eight thousand, eight hundred thirty-one".