3856912691 has 4 divisors (see below), whose sum is σ = 3892958712. Its totient is φ = 3820866672.

The previous prime is 3856912679. The next prime is 3856912693. The reversal of 3856912691 is 1962196583.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1962196583 = 11867 ⋅165349.

It is a cyclic number.

It is not a de Polignac number, because 3856912691 - 2⁶ = 3856912627 is a prime.

It is a super-2 number, since 2×3856912691² = 29751551011993722962, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3856912693) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18022850 + ... + 18023063.

It is an arithmetic number, because the mean of its divisors is an integer number (973239678).

Almost surely, 2^3856912691 is an apocalyptic number.

3856912691 is a deficient number, since it is larger than the sum of its proper divisors (36046021).

3856912691 is a wasteful number, since it uses less digits than its factorization.

3856912691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36046020.

The product of its digits is 699840, while the sum is 50.

The square root of 3856912691 is about 62104.0472996728. The cubic root of 3856912691 is about 1568.2426807229.

The spelling of 3856912691 in words is "three billion, eight hundred fifty-six million, nine hundred twelve thousand, six hundred ninety-one".