11509971 has 32 divisors (see below), whose sum is σ = 17611776. Its totient is φ = 6624000.

The previous prime is 11509963. The next prime is 11509973. The reversal of 11509971 is 17990511.

It is a happy number.

It is not a de Polignac number, because 11509971 - 2³ = 11509963 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (11509973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 63501 + ... + 63681.

It is an arithmetic number, because the mean of its divisors is an integer number (550368).

Almost surely, 2^11509971 is an apocalyptic number.

11509971 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

11509971 is a deficient number, since it is larger than the sum of its proper divisors (6101805).

11509971 is a wasteful number, since it uses less digits than its factorization.

11509971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 283.

The product of its (nonzero) digits is 2835, while the sum is 33.

The square root of 11509971 is about 3392.6348167759. The cubic root of 11509971 is about 225.7830886649.

The spelling of 11509971 in words is "eleven million, five hundred nine thousand, nine hundred seventy-one".