20402420040 has 96 divisors (see below), whose sum is σ = 66730393080. Its totient is φ = 5405976576.

The previous prime is 20402420033. The next prime is 20402420047. The reversal of 20402420040 is 4002420402.

20402420040 is a `hidden beast` number, since 20 + 402 + 4 + 200 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (20402420033) and next prime (20402420047).

It can be written as a sum of positive squares in 4 ways, for example, as 11300115204 + 9102304836 = 106302^2 + 95406^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 20402419995 and 20402420022.

It is not an unprimeable number, because it can be changed into a prime (20402420047) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 123969 + ... + 237008.

Almost surely, 2^20402420040 is an apocalyptic number.

20402420040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20402420040 is an abundant number, since it is smaller than the sum of its proper divisors (46327973040).

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

20402420040 is a wasteful number, since it uses less digits than its factorization.

20402420040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 361151 (or 361144 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 18.

Adding to 20402420040 its reverse (4002420402), we get a palindrome (24404840442).

The spelling of 20402420040 in words is "twenty billion, four hundred two million, four hundred twenty thousand, forty".