20812847281 has 16 divisors (see below), whose sum is σ = 21871013760. Its totient is φ = 19778532480.

The previous prime is 20812847233. The next prime is 20812847327. The reversal of 20812847281 is 18274821802.

It is a cyclic number.

It is not a de Polignac number, because 20812847281 - 2²⁷ = 20678629553 is a prime.

It is a super-2 number, since 2×20812847281² (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 (20812847221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1029436 + ... + 1049458.

It is an arithmetic number, because the mean of its divisors is an integer number (1366938360).

Almost surely, 2^20812847281 is an apocalyptic number.

It is an amenable number.

20812847281 is a deficient number, since it is larger than the sum of its proper divisors (1058166479).

20812847281 is a wasteful number, since it uses less digits than its factorization.

20812847281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20616.

The product of its (nonzero) digits is 114688, while the sum is 43.

The spelling of 20812847281 in words is "twenty billion, eight hundred twelve million, eight hundred forty-seven thousand, two hundred eighty-one".