11945991 has 8 divisors (see below), whose sum is σ = 15944704. Its totient is φ = 7955640.

The previous prime is 11945981. The next prime is 11946007. The reversal of 11945991 is 19954911.

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

It is not a de Polignac number, because 11945991 - 2¹³ = 11937799 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11945971) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3060 + ... + 5766.

It is an arithmetic number, because the mean of its divisors is an integer number (1993088).

Almost surely, 2^11945991 is an apocalyptic number.

11945991 is a deficient number, since it is larger than the sum of its proper divisors (3998713).

11945991 is a wasteful number, since it uses less digits than its factorization.

11945991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4181.

The product of its digits is 14580, while the sum is 39.

The square root of 11945991 is about 3456.2972962406. The cubic root of 11945991 is about 228.5988604167.

The spelling of 11945991 in words is "eleven million, nine hundred forty-five thousand, nine hundred ninety-one".