6397749081 has 6 divisors (see below), whose sum is σ = 9241193130. Its totient is φ = 4265166048.

The previous prime is 6397749047. The next prime is 6397749119. The reversal of 6397749081 is 1809477936.

It is a happy number.

6397749081 is a `hidden beast` number, since 6 + 3 + 9 + 77 + 490 + 81 = 666.

It can be written as a sum of positive squares in only one way, i.e., 6002375625 + 395373456 = 77475^2 + 19884^2 .

It is not a de Polignac number, because 6397749081 - 2¹¹ = 6397747033 is a prime.

It is a super-2 number, since 2×6397749081² = 81862386606872689122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6397749041) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 355430496 + ... + 355430513.

It is an arithmetic number, because the mean of its divisors is an integer number (1540198855).

Almost surely, 2^6397749081 is an apocalyptic number.

It is an amenable number.

6397749081 is a deficient number, since it is larger than the sum of its proper divisors (2843444049).

6397749081 is a wasteful number, since it uses less digits than its factorization.

6397749081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 710861015 (or 710861012 counting only the distinct ones).

The product of its (nonzero) digits is 2286144, while the sum is 54.

The square root of 6397749081 is about 79985.9305190607. The cubic root of 6397749081 is about 1856.4178445786.

The spelling of 6397749081 in words is "six billion, three hundred ninety-seven million, seven hundred forty-nine thousand, eighty-one".