3947351643 has 16 divisors (see below), whose sum is σ = 5893980160. Its totient is φ = 2610844488.

The previous prime is 3947351579. The next prime is 3947351651. The reversal of 3947351643 is 3461537493.

3947351643 is a `hidden beast` number, since 3 + 94 + 7 + 3 + 516 + 43 = 666.

It is not a de Polignac number, because 3947351643 - 2⁶ = 3947351579 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3947351743) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 572155 + ... + 579012.

It is an arithmetic number, because the mean of its divisors is an integer number (368373760).

Almost surely, 2^3947351643 is an apocalyptic number.

3947351643 is a deficient number, since it is larger than the sum of its proper divisors (1946628517).

3947351643 is a wasteful number, since it uses less digits than its factorization.

3947351643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1151303 (or 1151297 counting only the distinct ones).

The product of its digits is 816480, while the sum is 45.

The square root of 3947351643 is about 62827.9527201070. The cubic root of 3947351643 is about 1580.4057659711.

The spelling of 3947351643 in words is "three billion, nine hundred forty-seven million, three hundred fifty-one thousand, six hundred forty-three".