1291187 has 6 divisors (see below), whose sum is σ = 1316484. Its totient is φ = 1266360.

The previous prime is 1291177. The next prime is 1291193. The reversal of 1291187 is 7811921.

It is not a de Polignac number, because 1291187 - 2¹⁴ = 1274803 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1291117) 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 in 5 ways as a sum of consecutive naturals, for example, 3548 + ... + 3894.

It is an arithmetic number, because the mean of its divisors is an integer number (219414).

2^1291187 is an apocalyptic number.

1291187 is a deficient number, since it is larger than the sum of its proper divisors (25297).

1291187 is an frugal number, since it uses more digits than its factorization.

1291187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 469 (or 408 counting only the distinct ones).

The product of its digits is 1008, while the sum is 29.

The square root of 1291187 is about 1136.3040966220. The cubic root of 1291187 is about 108.8921020771.

The spelling of 1291187 in words is "one million, two hundred ninety-one thousand, one hundred eighty-seven".