6171830721 has 135 divisors (see below), whose sum is σ = 11371794291. Its totient is φ = 3325958496.

The previous prime is 6171830719. The next prime is 6171830747. The reversal of 6171830721 is 1270381716.

The square root of 6171830721 is 78561.

It is a perfect power (a square), and thus also a powerful number.

6171830721 is a `hidden beast` number, since 617 + 1 + 8 + 30 + 7 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 3236358321 + 2935472400 = 56889^2 + 54180^2 .

It is not a de Polignac number, because 6171830721 - 2¹ = 6171830719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6171832721) by changing a digit.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 143530926 + ... + 143530968.

Almost surely, 2^6171830721 is an apocalyptic number.

6171830721 is the 78561-st square number.

6171830721 is the 39281-st centered octagonal number.

It is an amenable number.

6171830721 is a deficient number, since it is larger than the sum of its proper divisors (5199963570).

6171830721 is an equidigital number, since it uses as much as digits as its factorization.

6171830721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170 (or 82 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The cubic root of 6171830721 is about 1834.3040936622.

Multiplying 6171830721 by its sum of digits (36), we get a square (222185905956 = 471366²).

The spelling of 6171830721 in words is "six billion, one hundred seventy-one million, eight hundred thirty thousand, seven hundred twenty-one".