1171391 has 4 divisors (see below), whose sum is σ = 1261512. Its totient is φ = 1081272.

The previous prime is 1171343. The next prime is 1171393. The reversal of 1171391 is 1931711.

1171391 = T₄₁₈ + T₄₁₉ + ... + T₄₃₀.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1171391 - 2¹⁸ = 909247 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1171393) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45041 + ... + 45066.

It is an arithmetic number, because the mean of its divisors is an integer number (315378).

2^1171391 is an apocalyptic number.

1171391 is a deficient number, since it is larger than the sum of its proper divisors (90121).

1171391 is an equidigital number, since it uses as much as digits as its factorization.

1171391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90120.

The product of its digits is 189, while the sum is 23.

The square root of 1171391 is about 1082.3081816193. The cubic root of 1171391 is about 105.4145666250.

The spelling of 1171391 in words is "one million, one hundred seventy-one thousand, three hundred ninety-one".