1291689125 has 16 divisors (see below), whose sum is σ = 1616150640. Its totient is φ = 1030708800.

The previous prime is 1291689089. The next prime is 1291689137. The reversal of 1291689125 is 5219861921.

It can be written as a sum of positive squares in 8 ways, for example, as 678185764 + 613503361 = 26042^2 + 24769^2 .

It is not a de Polignac number, because 1291689125 - 2⁸ = 1291688869 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36611 + ... + 62639.

It is an arithmetic number, because the mean of its divisors is an integer number (101009415).

Almost surely, 2^1291689125 is an apocalyptic number.

It is an amenable number.

1291689125 is a deficient number, since it is larger than the sum of its proper divisors (324461515).

1291689125 is an equidigital number, since it uses as much as digits as its factorization.

1291689125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26441 (or 26431 counting only the distinct ones).

The product of its digits is 77760, while the sum is 44.

The square root of 1291689125 is about 35940.0768641359. The cubic root of 1291689125 is about 1089.0621579845.

The spelling of 1291689125 in words is "one billion, two hundred ninety-one million, six hundred eighty-nine thousand, one hundred twenty-five".