13571991 has 12 divisors (see below), whose sum is σ = 19644768. Its totient is φ = 9029184.

The previous prime is 13571977. The next prime is 13572011. The reversal of 13571991 is 19917531.

It is not a de Polignac number, because 13571991 - 2⁶ = 13571927 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13571291) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4066 + ... + 6608.

It is an arithmetic number, because the mean of its divisors is an integer number (1637064).

Almost surely, 2^13571991 is an apocalyptic number.

13571991 is a deficient number, since it is larger than the sum of its proper divisors (6072777).

13571991 is a wasteful number, since it uses less digits than its factorization.

13571991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3142 (or 3139 counting only the distinct ones).

The product of its digits is 8505, while the sum is 36.

The square root of 13571991 is about 3684.0183224300. The cubic root of 13571991 is about 238.5326616925.

The spelling of 13571991 in words is "thirteen million, five hundred seventy-one thousand, nine hundred ninety-one".