20420040040 has 16 divisors (see below), whose sum is σ = 45945090180. Its totient is φ = 8168016000.

The previous prime is 20420040023. The next prime is 20420040049. The reversal of 20420040040 is 4004002402.

It can be written as a sum of positive squares in 2 ways, for example, as 20045462724 + 374577316 = 141582^2 + 19354^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20420039996 and 20420040023.

It is not an unprimeable number, because it can be changed into a prime (20420040049) 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, 255250461 + ... + 255250540.

Almost surely, 2^20420040040 is an apocalyptic number.

20420040040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20420040040 is an abundant number, since it is smaller than the sum of its proper divisors (25525050140).

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

20420040040 is a wasteful number, since it uses less digits than its factorization.

20420040040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 510501012 (or 510501008 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 16.

Adding to 20420040040 its reverse (4004002402), we get a palindrome (24424042442).

The spelling of 20420040040 in words is "twenty billion, four hundred twenty million, forty thousand, forty".