207898609681 has 27 divisors (see below), whose sum is σ = 246691102161. Its totient is φ = 174694307424.

The previous prime is 207898609661. The next prime is 207898609783. The reversal of 207898609681 is 186906898702.

The square root of 207898609681 is 455959.

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

It can be written as a sum of positive squares in 4 ways, for example, as 127573980625 + 80324629056 = 357175^2 + 283416^2 .

It is not a de Polignac number, because 207898609681 - 2⁵ = 207898609649 is a prime.

It is a super-2 number, since 2×207898609681² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (207898609651) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 169160175 + ... + 169161403.

Almost surely, 2^207898609681 is an apocalyptic number.

207898609681 is the 455959-th square number.

207898609681 is the 227980-th centered octagonal number.

It is an amenable number.

207898609681 is a deficient number, since it is larger than the sum of its proper divisors (38792492480).

207898609681 is an frugal number, since it uses more digits than its factorization.

207898609681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2578 (or 1289 counting only the distinct ones).

The product of its (nonzero) digits is 20901888, while the sum is 64.

Multiplying 207898609681 by its sum of digits (64), we get a square (13305511019584 = 3647672²).

The spelling of 207898609681 in words is "two hundred seven billion, eight hundred ninety-eight million, six hundred nine thousand, six hundred eighty-one".