20068681 has 4 divisors (see below), whose sum is σ = 20213200. Its totient is φ = 19924164.

The previous prime is 20068679. The next prime is 20068691. The reversal of 20068681 is 18686002.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18686002 = 2 ⋅9343001.

It is a cyclic number.

It is not a de Polignac number, because 20068681 - 2¹ = 20068679 is a prime.

It is a super-2 number, since 2×20068681² = 805503914159522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20068691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72051 + ... + 72328.

It is an arithmetic number, because the mean of its divisors is an integer number (5053300).

Almost surely, 2^20068681 is an apocalyptic number.

It is an amenable number.

20068681 is a deficient number, since it is larger than the sum of its proper divisors (144519).

20068681 is a wasteful number, since it uses less digits than its factorization.

20068681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144518.

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 20068681 is about 4479.8081432133. The cubic root of 20068681 is about 271.7521215269.

The spelling of 20068681 in words is "twenty million, sixty-eight thousand, six hundred eighty-one".