128001591 has 12 divisors (see below), whose sum is σ = 185152968. Its totient is φ = 85213584.

The previous prime is 128001553. The next prime is 128001637. The reversal of 128001591 is 195100821.

It is not a de Polignac number, because 128001591 - 2⁹ = 128001079 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128001791) 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, 3105 + ... + 16298.

It is an arithmetic number, because the mean of its divisors is an integer number (15429414).

Almost surely, 2^128001591 is an apocalyptic number.

128001591 is a deficient number, since it is larger than the sum of its proper divisors (57151377).

128001591 is a wasteful number, since it uses less digits than its factorization.

128001591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20142 (or 20139 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 27.

The square root of 128001591 is about 11313.7788116968. The cubic root of 128001591 is about 503.9705080060.

The spelling of 128001591 in words is "one hundred twenty-eight million, one thousand, five hundred ninety-one".