26709691761 has 21 divisors (see below), whose sum is σ = 40052835259. Its totient is φ = 17803519416.

The previous prime is 26709691753. The next prime is 26709691793. The reversal of 26709691761 is 16719690762.

The square root of 26709691761 is 163431.

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

It can be written as a sum of positive squares in only one way, i.e., 1948781025 + 24760910736 = 44145^2 + 157356^2 .

It is not a de Polignac number, because 26709691761 - 2³ = 26709691753 is a prime.

It is a super-2 number, since 2×26709691761² (a number of 22 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 = 26709691698 and 26709691707.

It is not an unprimeable number, because it can be changed into a prime (26709691721) by changing a digit.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 4409611 + ... + 4415663.

Almost surely, 2^26709691761 is an apocalyptic number.

26709691761 is the 163431-st square number.

26709691761 is the 81716-th centered octagonal number.

It is an amenable number.

26709691761 is a deficient number, since it is larger than the sum of its proper divisors (13343143498).

26709691761 is an frugal number, since it uses more digits than its factorization.

26709691761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12124 (or 6056 counting only the distinct ones).

The product of its (nonzero) digits is 1714608, while the sum is 54.

Subtracting from 26709691761 its reverse (16719690762), we obtain a palindrome (9990000999).

The spelling of 26709691761 in words is "twenty-six billion, seven hundred nine million, six hundred ninety-one thousand, seven hundred sixty-one".