1291491 has 16 divisors (see below), whose sum is σ = 1976320. Its totient is φ = 832680.

The previous prime is 1291489. The next prime is 1291501. The reversal of 1291491 is 1941921.

It is not a de Polignac number, because 1291491 - 2¹ = 1291489 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1291421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 66 + ... + 1608.

It is an arithmetic number, because the mean of its divisors is an integer number (123520).

2^1291491 is an apocalyptic number.

1291491 is a deficient number, since it is larger than the sum of its proper divisors (684829).

1291491 is a wasteful number, since it uses less digits than its factorization.

1291491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1583 (or 1577 counting only the distinct ones).

The product of its digits is 648, while the sum is 27.

The square root of 1291491 is about 1136.4378557581. The cubic root of 1291491 is about 108.9006473411.

The spelling of 1291491 in words is "one million, two hundred ninety-one thousand, four hundred ninety-one".