128538992 has 20 divisors (see below), whose sum is σ = 253744920. Its totient is φ = 63056448.

The previous prime is 128538979. The next prime is 128539001. The reversal of 128538992 is 299835821.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 74942 + ... + 76637.

It is an arithmetic number, because the mean of its divisors is an integer number (12687246).

Almost surely, 2^128538992 is an apocalyptic number.

It is an amenable number.

128538992 is a deficient number, since it is larger than the sum of its proper divisors (125205928).

128538992 is a wasteful number, since it uses less digits than its factorization.

128538992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151640 (or 151634 counting only the distinct ones).

The product of its digits is 311040, while the sum is 47.

The square root of 128538992 is about 11337.5037816973. The cubic root of 128538992 is about 504.6748120477.

The spelling of 128538992 in words is "one hundred twenty-eight million, five hundred thirty-eight thousand, nine hundred ninety-two".