1291325128 has 32 divisors (see below), whose sum is σ = 2450259000. Its totient is φ = 637959168.

The previous prime is 1291325107. The next prime is 1291325143. The reversal of 1291325128 is 8215231921.

It can be written as a sum of positive squares in 4 ways, for example, as 830707684 + 460617444 = 28822^2 + 21462^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1291325093 and 1291325102.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 313450 + ... + 317542.

Almost surely, 2^1291325128 is an apocalyptic number.

It is an amenable number.

1291325128 is a deficient number, since it is larger than the sum of its proper divisors (1158933872).

1291325128 is a wasteful number, since it uses less digits than its factorization.

1291325128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4561 (or 4557 counting only the distinct ones).

The product of its digits is 8640, while the sum is 34.

The square root of 1291325128 is about 35935.0125643501. The cubic root of 1291325128 is about 1088.9598494148.

The spelling of 1291325128 in words is "one billion, two hundred ninety-one million, three hundred twenty-five thousand, one hundred twenty-eight".