3945881613 has 16 divisors (see below), whose sum is σ = 5412277376. Its totient is φ = 2555271360.

The previous prime is 3945881581. The next prime is 3945881617. The reversal of 3945881613 is 3161885493.

It is not a de Polignac number, because 3945881613 - 2⁵ = 3945881581 is a prime.

It is a super-2 number, since 2×3945881613² = 31139963407622963538, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3945881617) 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, 39048 + ... + 97038.

It is an arithmetic number, because the mean of its divisors is an integer number (338267336).

Almost surely, 2^3945881613 is an apocalyptic number.

It is an amenable number.

3945881613 is a deficient number, since it is larger than the sum of its proper divisors (1466395763).

3945881613 is a wasteful number, since it uses less digits than its factorization.

3945881613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58644.

The product of its digits is 622080, while the sum is 48.

The square root of 3945881613 is about 62816.2527774461. The cubic root of 3945881613 is about 1580.2095557390.

The spelling of 3945881613 in words is "three billion, nine hundred forty-five million, eight hundred eighty-one thousand, six hundred thirteen".