128309436 has 36 divisors (see below), whose sum is σ = 331242912. Its totient is φ = 41859264.

The previous prime is 128309359. The next prime is 128309437. The reversal of 128309436 is 634903821.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×128309436² = 32926622733276192, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 128309436.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128309437) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 36225 + ... + 39608.

It is an arithmetic number, because the mean of its divisors is an integer number (9201192).

Almost surely, 2^128309436 is an apocalyptic number.

It is an amenable number.

128309436 is an abundant number, since it is smaller than the sum of its proper divisors (202933476).

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

128309436 is a wasteful number, since it uses less digits than its factorization.

128309436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75890 (or 75885 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 128309436 is about 11327.3755124477. The cubic root of 128309436 is about 504.3742024467.

The spelling of 128309436 in words is "one hundred twenty-eight million, three hundred nine thousand, four hundred thirty-six".