128538907 has 16 divisors (see below), whose sum is σ = 150400000. Its totient is φ = 109809000.

The previous prime is 128538899. The next prime is 128538919. The reversal of 128538907 is 709835821.

It is not a de Polignac number, because 128538907 - 2³ = 128538899 is a prime.

It is a super-2 number, since 2×128538907² = 33044501225509298, which contains 22 as substring.

It is the 11338-th Hogben number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128538107) by changing a digit.

It is a nontrivial repunit in base 11337.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 170782 + ... + 171532.

It is an arithmetic number, because the mean of its divisors is an integer number (9400000).

Almost surely, 2^128538907 is an apocalyptic number.

128538907 is a deficient number, since it is larger than the sum of its proper divisors (21861093).

128538907 is an frugal number, since it uses more digits than its factorization.

128538907 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1271 (or 1257 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 43.

The square root of 128538907 is about 11337.5000330761. The cubic root of 128538907 is about 504.6747008042.

The spelling of 128538907 in words is "one hundred twenty-eight million, five hundred thirty-eight thousand, nine hundred seven".