20668734593 has 4 divisors (see below), whose sum is σ = 22258637268. Its totient is φ = 19078831920.

The previous prime is 20668734533. The next prime is 20668734599. The reversal of 20668734593 is 39543786602.

It is a happy number.

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 8724867649 + 11943866944 = 93407^2 + 109288^2 .

It is a cyclic number.

It is not a de Polignac number, because 20668734593 - 2¹² = 20668730497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20668734599) 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, 794951318 + ... + 794951343.

It is an arithmetic number, because the mean of its divisors is an integer number (5564659317).

Almost surely, 2^20668734593 is an apocalyptic number.

It is an amenable number.

20668734593 is a deficient number, since it is larger than the sum of its proper divisors (1589902675).

20668734593 is a wasteful number, since it uses less digits than its factorization.

20668734593 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1589902674.

The product of its (nonzero) digits is 6531840, while the sum is 53.

The spelling of 20668734593 in words is "twenty billion, six hundred sixty-eight million, seven hundred thirty-four thousand, five hundred ninety-three".