1291831573 has 2 divisors, whose sum is σ = 1291831574. Its totient is φ = 1291831572.

The previous prime is 1291831543. The next prime is 1291831589. The reversal of 1291831573 is 3751381921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1275775524 + 16056049 = 35718^2 + 4007^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1291831573 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1291831523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 645915786 + 645915787.

It is an arithmetic number, because the mean of its divisors is an integer number (645915787).

Almost surely, 2^1291831573 is an apocalyptic number.

It is an amenable number.

1291831573 is a deficient number, since it is larger than the sum of its proper divisors (1).

1291831573 is an equidigital number, since it uses as much as digits as its factorization.

1291831573 is an evil number, because the sum of its binary digits is even.

The product of its digits is 45360, while the sum is 40.

The square root of 1291831573 is about 35942.0585526205. The cubic root of 1291831573 is about 1089.1021905849.

The spelling of 1291831573 in words is "one billion, two hundred ninety-one million, eight hundred thirty-one thousand, five hundred seventy-three".