26857637689 has 3 divisors (see below), whose sum is σ = 26857801573. Its totient is φ = 26857473806.

The previous prime is 26857637683. The next prime is 26857637699. The reversal of 26857637689 is 98673675862.

The square root of 26857637689 is 163883.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a de Polignac number, because none of the positive numbers 2^k-26857637689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (26857637683) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 81942 + ... + 245824.

Almost surely, 2^26857637689 is an apocalyptic number.

26857637689 is the 163883-rd square number.

26857637689 is the 81942-nd centered octagonal number.

It is an amenable number.

26857637689 is a deficient number, since it is larger than the sum of its proper divisors (163884).

26857637689 is an frugal number, since it uses more digits than its factorization.

26857637689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327766 (or 163883 counting only the distinct ones).

The product of its digits is 182891520, while the sum is 67.

The spelling of 26857637689 in words is "twenty-six billion, eight hundred fifty-seven million, six hundred thirty-seven thousand, six hundred eighty-nine".