128432251 has 4 divisors (see below), whose sum is σ = 129875400. Its totient is φ = 126989104.

The previous prime is 128432243. The next prime is 128432257. The reversal of 128432251 is 152234821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 152234821 = 19 ⋅8012359.

It is a cyclic number.

It is not a de Polignac number, because 128432251 - 2³ = 128432243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128432257) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 721441 + ... + 721618.

It is an arithmetic number, because the mean of its divisors is an integer number (32468850).

Almost surely, 2^128432251 is an apocalyptic number.

128432251 is a deficient number, since it is larger than the sum of its proper divisors (1443149).

128432251 is an equidigital number, since it uses as much as digits as its factorization.

128432251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1443148.

The product of its digits is 3840, while the sum is 28.

The square root of 128432251 is about 11332.7953744873. The cubic root of 128432251 is about 504.5350764662.

The spelling of 128432251 in words is "one hundred twenty-eight million, four hundred thirty-two thousand, two hundred fifty-one".