20853243959 has 4 divisors (see below), whose sum is σ = 21525929280. Its totient is φ = 20180558640.

The previous prime is 20853243889. The next prime is 20853243977. The reversal of 20853243959 is 95934235802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 95934235802 = 2 ⋅47967117901.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20853243959 is a prime.

It is a super-2 number, since 2×20853243959² (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 (20853242959) 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, 336342614 + ... + 336342675.

It is an arithmetic number, because the mean of its divisors is an integer number (5381482320).

Almost surely, 2^20853243959 is an apocalyptic number.

20853243959 is a deficient number, since it is larger than the sum of its proper divisors (672685321).

20853243959 is an equidigital number, since it uses as much as digits as its factorization.

20853243959 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 672685320.

The product of its (nonzero) digits is 2332800, while the sum is 50.

The spelling of 20853243959 in words is "twenty billion, eight hundred fifty-three million, two hundred forty-three thousand, nine hundred fifty-nine".