20938346689 has 4 divisors (see below), whose sum is σ = 22548988756. Its totient is φ = 19327704624.

The previous prime is 20938346687. The next prime is 20938346719. The reversal of 20938346689 is 98664383902.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2391992464 + 18546354225 = 48908^2 + 136185^2 .

It is a cyclic number.

It is not a de Polignac number, because 20938346689 - 2¹ = 20938346687 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20938346687) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 805321014 + ... + 805321039.

It is an arithmetic number, because the mean of its divisors is an integer number (5637247189).

Almost surely, 2^20938346689 is an apocalyptic number.

It is an amenable number.

20938346689 is a deficient number, since it is larger than the sum of its proper divisors (1610642067).

20938346689 is a wasteful number, since it uses less digits than its factorization.

20938346689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1610642066.

The product of its (nonzero) digits is 13436928, while the sum is 58.

The spelling of 20938346689 in words is "twenty billion, nine hundred thirty-eight million, three hundred forty-six thousand, six hundred eighty-nine".