20402400420 has 48 divisors (see below), whose sum is σ = 63474136320. Its totient is φ = 5440639968.

The previous prime is 20402400409. The next prime is 20402400427. The reversal of 20402400420 is 2400420402.

20402400420 is a `hidden beast` number, since 2 + 0 + 4 + 0 + 240 + 0 + 420 = 666.

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 = 20402400393 and 20402400402.

It is not an unprimeable number, because it can be changed into a prime (20402400427) 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, 18890572 + ... + 18891651.

It is an arithmetic number, because the mean of its divisors is an integer number (1322377840).

Almost surely, 2^20402400420 is an apocalyptic number.

20402400420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20402400420 is an abundant number, since it is smaller than the sum of its proper divisors (43071735900).

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

20402400420 is a wasteful number, since it uses less digits than its factorization.

20402400420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37782241 (or 37782233 counting only the distinct ones).

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

Adding to 20402400420 its reverse (2400420402), we get a palindrome (22802820822).

The spelling of 20402400420 in words is "twenty billion, four hundred two million, four hundred thousand, four hundred twenty".