128939712 has 56 divisors (see below), whose sum is σ = 372172992. Its totient is φ = 39072000.

The previous prime is 128939689. The next prime is 128939743. The reversal of 128939712 is 217939821.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28414 + ... + 32637.

Almost surely, 2^128939712 is an apocalyptic number.

128939712 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

128939712 is an abundant number, since it is smaller than the sum of its proper divisors (243233280).

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

128939712 is a wasteful number, since it uses less digits than its factorization.

128939712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61077 (or 61067 counting only the distinct ones).

The product of its digits is 54432, while the sum is 42.

The square root of 128939712 is about 11355.1623502264. The cubic root of 128939712 is about 505.1987088482.

The spelling of 128939712 in words is "one hundred twenty-eight million, nine hundred thirty-nine thousand, seven hundred twelve".