20853959281 has 3 divisors (see below), whose sum is σ = 20854103691. Its totient is φ = 20853814872.

The previous prime is 20853959251. The next prime is 20853959293. The reversal of 20853959281 is 18295935802.

The square root of 20853959281 is 144409.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 20848760881 + 5198400 = 144391^2 + 2280^2 .

It is not a de Polignac number, because 20853959281 - 2⁵ = 20853959249 is a prime.

It is a super-2 number, since 2×20853959281² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20853959201) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 72205 + ... + 216613.

It is an arithmetic number, because the mean of its divisors is an integer number (6951367897).

Almost surely, 2^20853959281 is an apocalyptic number.

20853959281 is the 144409-th square number.

20853959281 is the 72205-th centered octagonal number.

It is an amenable number.

20853959281 is a deficient number, since it is larger than the sum of its proper divisors (144410).

20853959281 is an frugal number, since it uses more digits than its factorization.

20853959281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288818 (or 144409 counting only the distinct ones).

The product of its (nonzero) digits is 1555200, while the sum is 52.

The spelling of 20853959281 in words is "twenty billion, eight hundred fifty-three million, nine hundred fifty-nine thousand, two hundred eighty-one".