11991506 has 8 divisors (see below), whose sum is σ = 18018444. Its totient is φ = 5985360.

The previous prime is 11991481. The next prime is 11991517. The reversal of 11991506 is 60519911.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 10182481 + 1809025 = 3191^2 + 1345^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×11991506² = 287592432296072, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3665 + ... + 6116.

Almost surely, 2^11991506 is an apocalyptic number.

11991506 is a deficient number, since it is larger than the sum of its proper divisors (6026938).

11991506 is an equidigital number, since it uses as much as digits as its factorization.

11991506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10396.

The product of its (nonzero) digits is 2430, while the sum is 32.

The square root of 11991506 is about 3462.8753948128. The cubic root of 11991506 is about 228.8888179673. Note that the first 4 decimals are identical.

The spelling of 11991506 in words is "eleven million, nine hundred ninety-one thousand, five hundred six".