20684026381 has 8 divisors (see below), whose sum is σ = 21540879000. Its totient is φ = 19836747840.

The previous prime is 20684026379. The next prime is 20684026403. The reversal of 20684026381 is 18362048602.

It can be written as a sum of positive squares in 4 ways, for example, as 8462281 + 20675564100 = 2909^2 + 143790^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20684026381 - 2¹ = 20684026379 is a prime.

It is a super-2 number, since 2×20684026381² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20684026331) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2389110 + ... + 2397751.

It is an arithmetic number, because the mean of its divisors is an integer number (2692609875).

Almost surely, 2^20684026381 is an apocalyptic number.

It is an amenable number.

20684026381 is a deficient number, since it is larger than the sum of its proper divisors (856852619).

20684026381 is a wasteful number, since it uses less digits than its factorization.

20684026381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4787039.

The product of its (nonzero) digits is 110592, while the sum is 40.

The spelling of 20684026381 in words is "twenty billion, six hundred eighty-four million, twenty-six thousand, three hundred eighty-one".