3995643947 has 4 divisors (see below), whose sum is σ = 4080657696. Its totient is φ = 3910630200.

The previous prime is 3995643937. The next prime is 3995643991. The reversal of 3995643947 is 7493465993.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3995643947 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3995643937) 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, 42506804 + ... + 42506897.

It is an arithmetic number, because the mean of its divisors is an integer number (1020164424).

Almost surely, 2^3995643947 is an apocalyptic number.

3995643947 is a deficient number, since it is larger than the sum of its proper divisors (85013749).

3995643947 is an equidigital number, since it uses as much as digits as its factorization.

3995643947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85013748.

The product of its digits is 22044960, while the sum is 59.

The square root of 3995643947 is about 63211.1061997811. The cubic root of 3995643947 is about 1586.8246090733.

The spelling of 3995643947 in words is "three billion, nine hundred ninety-five million, six hundred forty-three thousand, nine hundred forty-seven".