128111457 has 4 divisors (see below), whose sum is σ = 170815280. Its totient is φ = 85407636.

The previous prime is 128111453. The next prime is 128111461. The reversal of 128111457 is 754111821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 754111821 = 3 ⋅251370607.

It is an interprime number because it is at equal distance from previous prime (128111453) and next prime (128111461).

It is not a de Polignac number, because 128111457 - 2² = 128111453 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128111453) 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, 21351907 + ... + 21351912.

It is an arithmetic number, because the mean of its divisors is an integer number (42703820).

Almost surely, 2^128111457 is an apocalyptic number.

It is an amenable number.

128111457 is a deficient number, since it is larger than the sum of its proper divisors (42703823).

128111457 is an equidigital number, since it uses as much as digits as its factorization.

128111457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42703822.

The product of its digits is 2240, while the sum is 30.

The square root of 128111457 is about 11318.6331771994. The cubic root of 128111457 is about 504.1146556672.

The spelling of 128111457 in words is "one hundred twenty-eight million, one hundred eleven thousand, four hundred fifty-seven".