128631 has 8 divisors (see below), whose sum is σ = 174960. Its totient is φ = 84032.

The previous prime is 128629. The next prime is 128657. The reversal of 128631 is 136821.

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

It is a cyclic number.

It is not a de Polignac number, because 128631 - 2¹ = 128629 is a prime.

It is a super-2 number, since 2×128631² = 33091868322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 128598 and 128607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 246 + ... + 563.

It is an arithmetic number, because the mean of its divisors is an integer number (21870).

2¹²⁸⁶³¹ is an apocalyptic number.

128631 is a deficient number, since it is larger than the sum of its proper divisors (46329).

128631 is an equidigital number, since it uses as much as digits as its factorization.

128631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 865.

The product of its digits is 288, while the sum is 21.

The square root of 128631 is about 358.6516415688. The cubic root of 128631 is about 50.4795198463.

The spelling of 128631 in words is "one hundred twenty-eight thousand, six hundred thirty-one".