3947636447 has 2 divisors, whose sum is σ = 3947636448. Its totient is φ = 3947636446.

The previous prime is 3947636443. The next prime is 3947636489. The reversal of 3947636447 is 7446367493.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 3947636447 - 2² = 3947636443 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3947636443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1973818223 + 1973818224.

It is an arithmetic number, because the mean of its divisors is an integer number (1973818224).

Almost surely, 2^3947636447 is an apocalyptic number.

3947636447 is a deficient number, since it is larger than the sum of its proper divisors (1).

3947636447 is an equidigital number, since it uses as much as digits as its factorization.

3947636447 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9144576, while the sum is 53.

The square root of 3947636447 is about 62830.2192181437. The cubic root of 3947636447 is about 1580.4437741599.

The spelling of 3947636447 in words is "three billion, nine hundred forty-seven million, six hundred thirty-six thousand, four hundred forty-seven".