128421436 has 24 divisors (see below), whose sum is σ = 264028464. Its totient is φ = 53882880.

The previous prime is 128421431. The next prime is 128421457. The reversal of 128421436 is 634124821.

It is a junction number, because it is equal to n+sod(n) for n = 128421398 and 128421407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128421431) 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, 111685 + ... + 112828.

It is an arithmetic number, because the mean of its divisors is an integer number (11001186).

Almost surely, 2^128421436 is an apocalyptic number.

It is an amenable number.

128421436 is an abundant number, since it is smaller than the sum of its proper divisors (135607028).

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

128421436 is a wasteful number, since it uses less digits than its factorization.

128421436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224541 (or 224539 counting only the distinct ones).

The product of its digits is 9216, while the sum is 31.

The square root of 128421436 is about 11332.3182094398. The cubic root of 128421436 is about 504.5209141355.

The spelling of 128421436 in words is "one hundred twenty-eight million, four hundred twenty-one thousand, four hundred thirty-six".