3121665671 has 4 divisors (see below), whose sum is σ = 3121822200. Its totient is φ = 3121509144.

The previous prime is 3121665661. The next prime is 3121665689. The reversal of 3121665671 is 1765661213.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1765661213 = 20807 ⋅84859.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3121665671 is a prime.

It is a super-2 number, since 2×3121665671² = 19489593122999760482, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3121665611) 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, 43076 + ... + 89993.

It is an arithmetic number, because the mean of its divisors is an integer number (780455550).

Almost surely, 2^3121665671 is an apocalyptic number.

3121665671 is a deficient number, since it is larger than the sum of its proper divisors (156529).

3121665671 is a wasteful number, since it uses less digits than its factorization.

3121665671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156528.

The product of its digits is 45360, while the sum is 38.

The square root of 3121665671 is about 55871.8683328202. The cubic root of 3121665671 is about 1461.4887034120.

The spelling of 3121665671 in words is "three billion, one hundred twenty-one million, six hundred sixty-five thousand, six hundred seventy-one".