11947945 has 4 divisors (see below), whose sum is σ = 14337540. Its totient is φ = 9558352.

The previous prime is 11947931. The next prime is 11947961. The reversal of 11947945 is 54974911.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54974911 = 103 ⋅533737.

It can be written as a sum of positive squares in 2 ways, for example, as 1605289 + 10342656 = 1267^2 + 3216^2 .

It is a cyclic number.

It is not a de Polignac number, because 11947945 - 2⁹ = 11947433 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 11947898 and 11947907.

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, 1194790 + ... + 1194799.

It is an arithmetic number, because the mean of its divisors is an integer number (3584385).

Almost surely, 2^11947945 is an apocalyptic number.

It is an amenable number.

11947945 is a deficient number, since it is larger than the sum of its proper divisors (2389595).

11947945 is an equidigital number, since it uses as much as digits as its factorization.

11947945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2389594.

The product of its digits is 45360, while the sum is 40.

The square root of 11947945 is about 3456.5799571253. The cubic root of 11947945 is about 228.6113236724.

The spelling of 11947945 in words is "eleven million, nine hundred forty-seven thousand, nine hundred forty-five".