128889988 has 24 divisors (see below), whose sum is σ = 239766912. Its totient is φ = 60415104.

The previous prime is 128889979. The next prime is 128889989. The reversal of 128889988 is 889988821.

It is a happy number.

It is a super-2 number, since 2×128889988² = 33225258013280288, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (128889989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14281 + ... + 21487.

It is an arithmetic number, because the mean of its divisors is an integer number (9990288).

Almost surely, 2^128889988 is an apocalyptic number.

It is an amenable number.

128889988 is a deficient number, since it is larger than the sum of its proper divisors (110876924).

128889988 is a wasteful number, since it uses less digits than its factorization.

128889988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7491 (or 7489 counting only the distinct ones).

The product of its digits is 5308416, while the sum is 61.

The square root of 128889988 is about 11352.9726503678. The cubic root of 128889988 is about 505.1337592941.

The spelling of 128889988 in words is "one hundred twenty-eight million, eight hundred eighty-nine thousand, nine hundred eighty-eight".