128211993 has 48 divisors (see below), whose sum is σ = 234148096. Its totient is φ = 65784960.

The previous prime is 128211991. The next prime is 128212033. The reversal of 128211993 is 399112821.

It is not a de Polignac number, because 128211993 - 2¹ = 128211991 is a prime.

It is not an unprimeable number, because it can be changed into a prime (128211991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 28188 + ... + 32418.

Almost surely, 2^128211993 is an apocalyptic number.

128211993 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

128211993 is a deficient number, since it is larger than the sum of its proper divisors (105936103).

128211993 is a wasteful number, since it uses less digits than its factorization.

128211993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4294 (or 4291 counting only the distinct ones).

The product of its digits is 7776, while the sum is 36.

The square root of 128211993 is about 11323.0734785216. The cubic root of 128211993 is about 504.2464898800.

The spelling of 128211993 in words is "one hundred twenty-eight million, two hundred eleven thousand, nine hundred ninety-three".