128988634 has 4 divisors (see below), whose sum is σ = 193482954. Its totient is φ = 64494316.

The previous prime is 128988631. The next prime is 128988637. The reversal of 128988634 is 436889821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 436889821 = 37 ⋅11807833.

It is an interprime number because it is at equal distance from previous prime (128988631) and next prime (128988637).

It can be written as a sum of positive squares in only one way, i.e., 122213025 + 6775609 = 11055^2 + 2603^2 .

It is not an unprimeable number, because it can be changed into a prime (128988631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32247157 + ... + 32247160.

Almost surely, 2^128988634 is an apocalyptic number.

128988634 is a deficient number, since it is larger than the sum of its proper divisors (64494320).

128988634 is an equidigital number, since it uses as much as digits as its factorization.

128988634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64494319.

The product of its digits is 663552, while the sum is 49.

The square root of 128988634 is about 11357.3163203285. The cubic root of 128988634 is about 505.2625945348.

The spelling of 128988634 in words is "one hundred twenty-eight million, nine hundred eighty-eight thousand, six hundred thirty-four".