6166721871 has 24 divisors (see below), whose sum is σ = 9388421120. Its totient is φ = 3889737936.

The previous prime is 6166721839. The next prime is 6166721921. The reversal of 6166721871 is 1781276616.

6166721871 is a `hidden beast` number, since 616 + 6 + 7 + 21 + 8 + 7 + 1 = 666.

It is not a de Polignac number, because 6166721871 - 2⁵ = 6166721839 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6166721471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 111666 + ... + 157488.

Almost surely, 2^6166721871 is an apocalyptic number.

6166721871 is a deficient number, since it is larger than the sum of its proper divisors (3221699249).

6166721871 is a wasteful number, since it uses less digits than its factorization.

6166721871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46635 (or 46632 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The square root of 6166721871 is about 78528.4780891620. The cubic root of 6166721871 is about 1833.7978272717.

It can be divided in two parts, 61667 and 21871, that added together give a palindrome (83538).

The spelling of 6166721871 in words is "six billion, one hundred sixty-six million, seven hundred twenty-one thousand, eight hundred seventy-one".