20704243057 has 4 divisors (see below), whose sum is σ = 21793940080. Its totient is φ = 19614546036.

The previous prime is 20704243009. The next prime is 20704243061. The reversal of 20704243057 is 75034240702.

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.

It is a cyclic number.

It is not a de Polignac number, because 20704243057 - 2¹¹ = 20704241009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20704243457) 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, 544848483 + ... + 544848520.

It is an arithmetic number, because the mean of its divisors is an integer number (5448485020).

Almost surely, 2^20704243057 is an apocalyptic number.

It is an amenable number.

20704243057 is a deficient number, since it is larger than the sum of its proper divisors (1089697023).

20704243057 is a wasteful number, since it uses less digits than its factorization.

20704243057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1089697022.

The product of its (nonzero) digits is 47040, while the sum is 34.

Adding to 20704243057 its reverse (75034240702), we get a palindrome (95738483759).

The spelling of 20704243057 in words is "twenty billion, seven hundred four million, two hundred forty-three thousand, fifty-seven".