20428202440 has 32 divisors (see below), whose sum is σ = 47084519160. Its totient is φ = 7971980800.

The previous prime is 20428202419. The next prime is 20428202441. The reversal of 20428202440 is 4420282402.

It can be written as a sum of positive squares in 4 ways, for example, as 5087398276 + 15340804164 = 71326^2 + 123858^2 .

It is a super-2 number, since 2×20428202440² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20428202399 and 20428202408.

It is not an unprimeable number, because it can be changed into a prime (20428202441) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6226471 + ... + 6229750.

Almost surely, 2^20428202440 is an apocalyptic number.

20428202440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20428202440 is an abundant number, since it is smaller than the sum of its proper divisors (26656316720).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20428202440 is a wasteful number, since it uses less digits than its factorization.

20428202440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12456273 (or 12456269 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 28.

Adding to 20428202440 its reverse (4420282402), we get a palindrome (24848484842).

The spelling of 20428202440 in words is "twenty billion, four hundred twenty-eight million, two hundred two thousand, four hundred forty".