1261112591 has 2 divisors, whose sum is σ = 1261112592. Its totient is φ = 1261112590.

The previous prime is 1261112569. The next prime is 1261112623. The reversal of 1261112591 is 1952111621.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1261112591 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1261112521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630556295 + 630556296.

It is an arithmetic number, because the mean of its divisors is an integer number (630556296).

Almost surely, 2^1261112591 is an apocalyptic number.

1261112591 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261112591 is an equidigital number, since it uses as much as digits as its factorization.

1261112591 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1080, while the sum is 29.

The square root of 1261112591 is about 35512.1470908195. The cubic root of 1261112591 is about 1080.4001120957.

The spelling of 1261112591 in words is "one billion, two hundred sixty-one million, one hundred twelve thousand, five hundred ninety-one".