128912436 has 18 divisors (see below), whose sum is σ = 325862082. Its totient is φ = 42970800.

The previous prime is 128912429. The next prime is 128912449. The reversal of 128912436 is 634219821.

It can be written as a sum of positive squares in only one way, i.e., 123876900 + 5035536 = 11130^2 + 2244^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 3580901 = 128912436 / (1 + 2 + 8 + 9 + 1 + 2 + 4 + 3 + 6).

It is a self number, because there is not a number n which added to its sum of digits gives 128912436.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1790415 + ... + 1790486.

It is an arithmetic number, because the mean of its divisors is an integer number (18103449).

Almost surely, 2^128912436 is an apocalyptic number.

It is an amenable number.

128912436 is an abundant number, since it is smaller than the sum of its proper divisors (196949646).

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

128912436 is a wasteful number, since it uses less digits than its factorization.

128912436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3580911 (or 3580906 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 128912436 is about 11353.9612470714. The cubic root of 128912436 is about 505.1630829692.

The spelling of 128912436 in words is "one hundred twenty-eight million, nine hundred twelve thousand, four hundred thirty-six".