849698647681 has 81 divisors (see below), whose sum is σ = 1011075467931. Its totient is φ = 713598971904.

The previous prime is 849698647673. The next prime is 849698647709. The reversal of 849698647681 is 186746896948.

The square root of 849698647681 is 921791.

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

It can be written as a sum of positive squares in 13 ways, for example, as 547326234225 + 302372413456 = 739815^2 + 549884^2 .

It is not a de Polignac number, because 849698647681 - 2³ = 849698647673 is a prime.

It is a super-2 number, since 2×849698647681² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 849698647598 and 849698647607.

It is not an unprimeable number, because it can be changed into a prime (849698647661) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 8759779825 + ... + 8759779921.

Almost surely, 2^849698647681 is an apocalyptic number.

849698647681 is the 921791-st square number.

849698647681 is the 460896-th centered octagonal number.

It is an amenable number.

849698647681 is a deficient number, since it is larger than the sum of its proper divisors (161376820250).

849698647681 is an equidigital number, since it uses as much as digits as its factorization.

849698647681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340 (or 170 counting only the distinct ones).

The product of its digits is 1003290624, while the sum is 76.

The spelling of 849698647681 in words is "eight hundred forty-nine billion, six hundred ninety-eight million, six hundred forty-seven thousand, six hundred eighty-one".