20400420404400 has 60 divisors (see below), whose sum is σ = 65349346699272. Its totient is φ = 5440112107520.

The previous prime is 20400420404389. The next prime is 20400420404459. The reversal of 20400420404400 is 440402400402.

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8500173969 + ... + 8500176368.

Almost surely, 2^{20400420404400} is an apocalyptic number.

20400420404400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20400420404400 is an abundant number, since it is smaller than the sum of its proper divisors (44948926294872).

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

20400420404400 is a wasteful number, since it uses less digits than its factorization.

20400420404400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17000350358 (or 17000350347 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 24.

Adding to 20400420404400 its reverse (440402400402), we get a palindrome (20840822804802).

The spelling of 20400420404400 in words is "twenty trillion, four hundred billion, four hundred twenty million, four hundred four thousand, four hundred".