1230128557 has 4 divisors (see below), whose sum is σ = 1405861216. Its totient is φ = 1054395900.

The previous prime is 1230128519. The next prime is 1230128579. The reversal of 1230128557 is 7558210321.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1230128557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1230128507) 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, 87866319 + ... + 87866332.

It is an arithmetic number, because the mean of its divisors is an integer number (351465304).

Almost surely, 2^1230128557 is an apocalyptic number.

It is an amenable number.

1230128557 is a deficient number, since it is larger than the sum of its proper divisors (175732659).

1230128557 is an equidigital number, since it uses as much as digits as its factorization.

1230128557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175732658.

The product of its (nonzero) digits is 16800, while the sum is 34.

The square root of 1230128557 is about 35073.1885776016. The cubic root of 1230128557 is about 1071.4785966492.

Adding to 1230128557 its reverse (7558210321), we get a palindrome (8788338878).

The spelling of 1230128557 in words is "one billion, two hundred thirty million, one hundred twenty-eight thousand, five hundred fifty-seven".