11991567 has 16 divisors (see below), whose sum is σ = 18328320. Its totient is φ = 6831552.

The previous prime is 11991523. The next prime is 11991583. The reversal of 11991567 is 76519911.

It is not a de Polignac number, because 11991567 - 2¹¹ = 11989519 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11991517) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8659 + ... + 9947.

It is an arithmetic number, because the mean of its divisors is an integer number (1145520).

Almost surely, 2^11991567 is an apocalyptic number.

11991567 is a deficient number, since it is larger than the sum of its proper divisors (6336753).

11991567 is a wasteful number, since it uses less digits than its factorization.

11991567 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1742.

The product of its digits is 17010, while the sum is 39.

The square root of 11991567 is about 3462.8842025110. The cubic root of 11991567 is about 228.8892060807.

The spelling of 11991567 in words is "eleven million, nine hundred ninety-one thousand, five hundred sixty-seven".