3945643643 has 8 divisors (see below), whose sum is σ = 3963096720. Its totient is φ = 3928207360.

The previous prime is 3945643621. The next prime is 3945643673. The reversal of 3945643643 is 3463465493.

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

It is a cyclic number.

It is not a de Polignac number, because 3945643643 - 2¹⁸ = 3945381499 is a prime.

It is a super-2 number, since 2×3945643643² = 31136207515092622898, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3945643613) 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, 760448 + ... + 765618.

It is an arithmetic number, because the mean of its divisors is an integer number (495387090).

Almost surely, 2^3945643643 is an apocalyptic number.

3945643643 is a deficient number, since it is larger than the sum of its proper divisors (17453077).

3945643643 is a wasteful number, since it uses less digits than its factorization.

3945643643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8397.

The product of its digits is 2799360, while the sum is 47.

The square root of 3945643643 is about 62814.3585734981. The cubic root of 3945643643 is about 1580.1777884379.

The spelling of 3945643643 in words is "three billion, nine hundred forty-five million, six hundred forty-three thousand, six hundred forty-three".