128691232 has 12 divisors (see below), whose sum is σ = 253360926. Its totient is φ = 64345600.

The previous prime is 128691229. The next prime is 128691239. The reversal of 128691232 is 232196821.

It can be written as a sum of positive squares in only one way, i.e., 74580496 + 54110736 = 8636^2 + 7356^2 .

It is a super-2 number, since 2×128691232² = 33122866387355648, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (128691239) 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 as a sum of consecutive naturals, namely, 2010769 + ... + 2010832.

Almost surely, 2^128691232 is an apocalyptic number.

It is an amenable number.

128691232 is a deficient number, since it is larger than the sum of its proper divisors (124669694).

128691232 is an equidigital number, since it uses as much as digits as its factorization.

128691232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4021611 (or 4021603 counting only the distinct ones).

The product of its digits is 10368, while the sum is 34.

The square root of 128691232 is about 11344.2157948445. The cubic root of 128691232 is about 504.8739769841.

The spelling of 128691232 in words is "one hundred twenty-eight million, six hundred ninety-one thousand, two hundred thirty-two".