20438240281 has 4 divisors (see below), whose sum is σ = 20442271012. Its totient is φ = 20434209552.

The previous prime is 20438240213. The next prime is 20438240287. The reversal of 20438240281 is 18204283402.

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 14164808256 + 6273432025 = 119016^2 + 79205^2 .

It is a cyclic number.

It is not a de Polignac number, because 20438240281 - 2⁹ = 20438239769 is a prime.

It is a super-2 number, since 2×20438240281² (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 (20438240287) 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, 2007750 + ... + 2017903.

It is an arithmetic number, because the mean of its divisors is an integer number (5110567753).

Almost surely, 2^20438240281 is an apocalyptic number.

It is an amenable number.

20438240281 is a deficient number, since it is larger than the sum of its proper divisors (4030731).

20438240281 is an equidigital number, since it uses as much as digits as its factorization.

20438240281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4030730.

The product of its (nonzero) digits is 24576, while the sum is 34.

The spelling of 20438240281 in words is "twenty billion, four hundred thirty-eight million, two hundred forty thousand, two hundred eighty-one".