11999971 has 4 divisors (see below), whose sum is σ = 12009712. Its totient is φ = 11990232.

The previous prime is 11999941. The next prime is 11999987. The reversal of 11999971 is 17999911.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 11999971 - 2⁷ = 11999843 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11999941) 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, 2700 + ... + 5593.

It is an arithmetic number, because the mean of its divisors is an integer number (3002428).

Almost surely, 2^11999971 is an apocalyptic number.

11999971 is a deficient number, since it is larger than the sum of its proper divisors (9741).

11999971 is an equidigital number, since it uses as much as digits as its factorization.

11999971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9740.

The product of its digits is 45927, while the sum is 46.

The square root of 11999971 is about 3464.0974293458. The cubic root of 11999971 is about 228.9426640843.

The spelling of 11999971 in words is "eleven million, nine hundred ninety-nine thousand, nine hundred seventy-one".