1291637 has 2 divisors, whose sum is σ = 1291638. Its totient is φ = 1291636.

The previous prime is 1291603. The next prime is 1291669. The reversal of 1291637 is 7361921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 988036 + 303601 = 994^2 + 551^2 .

It is a cyclic number.

It is not a de Polignac number, because 1291637 - 2¹² = 1287541 is a prime.

It is a super-2 number, since 2×1291637² = 3336652279538, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1290637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 645818 + 645819.

It is an arithmetic number, because the mean of its divisors is an integer number (645819).

2^1291637 is an apocalyptic number.

It is an amenable number.

1291637 is a deficient number, since it is larger than the sum of its proper divisors (1).

1291637 is an equidigital number, since it uses as much as digits as its factorization.

1291637 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2268, while the sum is 29.

The square root of 1291637 is about 1136.5020897473. The cubic root of 1291637 is about 108.9047508400.

The spelling of 1291637 in words is "one million, two hundred ninety-one thousand, six hundred thirty-seven".