3943961691 has 16 divisors (see below), whose sum is σ = 5453978400. Its totient is φ = 2532094208.

The previous prime is 3943961687. The next prime is 3943961711. The reversal of 3943961691 is 1961693493.

It is a cyclic number.

It is not a de Polignac number, because 3943961691 - 2² = 3943961687 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3943961621) 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, 24426 + ... + 92111.

It is an arithmetic number, because the mean of its divisors is an integer number (340873650).

Almost surely, 2^3943961691 is an apocalyptic number.

3943961691 is a deficient number, since it is larger than the sum of its proper divisors (1510016709).

3943961691 is a wasteful number, since it uses less digits than its factorization.

3943961691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116958.

The product of its digits is 944784, while the sum is 51.

The square root of 3943961691 is about 62800.9688699147. The cubic root of 3943961691 is about 1579.9532233922.

The spelling of 3943961691 in words is "three billion, nine hundred forty-three million, nine hundred sixty-one thousand, six hundred ninety-one".