128436889 has 9 divisors (see below), whose sum is σ = 149498517. Its totient is φ = 110020764.

The previous prime is 128436883. The next prime is 128436901. The reversal of 128436889 is 988634821.

The square root of 128436889 is 11333.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 128436889 - 2³ = 128436881 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is not an unprimeable number, because it can be changed into a prime (128436881) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 78522 + ... + 80140.

Almost surely, 2^128436889 is an apocalyptic number.

128436889 is the 11333-rd square number.

128436889 is the 5667-th centered octagonal number.

It is an amenable number.

128436889 is a deficient number, since it is larger than the sum of its proper divisors (21061628).

128436889 is an frugal number, since it uses more digits than its factorization.

128436889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3252 (or 1626 counting only the distinct ones).

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

The cubic root of 128436889 is about 504.5411497214.

Multiplying 128436889 by its sum of digits (49), we get a square (6293407561 = 79331²).

128436889 divided by its sum of digits (49) gives a square (2621161 = 1619²).

The spelling of 128436889 in words is "one hundred twenty-eight million, four hundred thirty-six thousand, eight hundred eighty-nine".