1291431 has 8 divisors (see below), whose sum is σ = 1750384. Its totient is φ = 846720.

The previous prime is 1291421. The next prime is 1291447. The reversal of 1291431 is 1341921.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1291431 - 2¹⁷ = 1160359 is a prime.

It is a super-2 number, since 2×1291431² = 3335588055522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1291398 and 1291407.

It is a congruent 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 7 ways as a sum of consecutive naturals, for example, 3346 + ... + 3711.

It is an arithmetic number, because the mean of its divisors is an integer number (218798).

2^1291431 is an apocalyptic number.

1291431 is a deficient number, since it is larger than the sum of its proper divisors (458953).

1291431 is an equidigital number, since it uses as much as digits as its factorization.

1291431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7121.

The product of its digits is 216, while the sum is 21.

The square root of 1291431 is about 1136.4114571756. The cubic root of 1291431 is about 108.8989608821.

The spelling of 1291431 in words is "one million, two hundred ninety-one thousand, four hundred thirty-one".