128987136 has 78 divisors (see below), whose sum is σ = 372690500. Its totient is φ = 42983424.

The previous prime is 128987119. The next prime is 128987137. The reversal of 128987136 is 631789821.

It is a junction number, because it is equal to n+sod(n) for n = 128987091 and 128987100.

It is not an unprimeable number, because it can be changed into a prime (128987137) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35115 + ... + 38613.

Almost surely, 2^128987136 is an apocalyptic number.

128987136 is a gapful number since it is divisible by the number (16) 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 128987136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (186345250).

128987136 is an abundant number, since it is smaller than the sum of its proper divisors (243703364).

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

128987136 is an equidigital number, since it uses as much as digits as its factorization.

128987136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3529 (or 3504 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The square root of 128987136 is about 11357.2503714588. The cubic root of 128987136 is about 505.2606385839.

The spelling of 128987136 in words is "one hundred twenty-eight million, nine hundred eighty-seven thousand, one hundred thirty-six".