20678701681 has 6 divisors (see below), whose sum is σ = 22729482146. Its totient is φ = 18798819600.

The previous prime is 20678701679. The next prime is 20678701727. The reversal of 20678701681 is 18610787602.

It can be written as a sum of positive squares in only one way, i.e., 19639219600 + 1039482081 = 140140^2 + 32241^2 .

It is not a de Polignac number, because 20678701681 - 2¹ = 20678701679 is a prime.

It is a super-2 number, since 2×20678701681² (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 (20678701481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 85449060 + ... + 85449301.

Almost surely, 2^20678701681 is an apocalyptic number.

It is an amenable number.

20678701681 is a deficient number, since it is larger than the sum of its proper divisors (2050780465).

20678701681 is a wasteful number, since it uses less digits than its factorization.

20678701681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170898383 (or 170898372 counting only the distinct ones).

The product of its (nonzero) digits is 225792, while the sum is 46.

The spelling of 20678701681 in words is "twenty billion, six hundred seventy-eight million, seven hundred one thousand, six hundred eighty-one".