11571971 has 4 divisors (see below), whose sum is σ = 11614944. Its totient is φ = 11529000.

The previous prime is 11571949. The next prime is 11571983. The reversal of 11571971 is 17917511.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17917511 = 1279 ⋅14009.

It is a cyclic number.

It is not a de Polignac number, because 11571971 - 2¹⁴ = 11555587 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11571941) 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, 21080 + ... + 21621.

It is an arithmetic number, because the mean of its divisors is an integer number (2903736).

Almost surely, 2^11571971 is an apocalyptic number.

11571971 is a deficient number, since it is larger than the sum of its proper divisors (42973).

11571971 is an equidigital number, since it uses as much as digits as its factorization.

11571971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42972.

The product of its digits is 2205, while the sum is 32.

The square root of 11571971 is about 3401.7599856545. The cubic root of 11571971 is about 226.1877665285.

The spelling of 11571971 in words is "eleven million, five hundred seventy-one thousand, nine hundred seventy-one".