18894976681 has 27 divisors (see below), whose sum is σ = 22368241701. Its totient is φ = 15914453184.

The previous prime is 18894976657. The next prime is 18894976699. The reversal of 18894976681 is 18667949881.

The square root of 18894976681 is 137459.

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 3696032025 + 15198944656 = 60795^2 + 123284^2 .

It is not a de Polignac number, because 18894976681 - 2¹¹ = 18894974633 is a prime.

It is a super-2 number, since 2×18894976681² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18894976081) 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, 70241415 + ... + 70241683.

Almost surely, 2^18894976681 is an apocalyptic number.

18894976681 is the 137459-th square number.

18894976681 is the 68730-th centered octagonal number.

It is an amenable number.

18894976681 is a deficient number, since it is larger than the sum of its proper divisors (3473265020).

18894976681 is an frugal number, since it uses more digits than its factorization.

18894976681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 698 (or 349 counting only the distinct ones).

The product of its digits is 41803776, while the sum is 67.

The spelling of 18894976681 in words is "eighteen billion, eight hundred ninety-four million, nine hundred seventy-six thousand, six hundred eighty-one".