20420400404440 has 32 divisors (see below), whose sum is σ = 45946278792000. Its totient is φ = 8168092982784.

The previous prime is 20420400404431. The next prime is 20420400404471. The reversal of 20420400404440 is 4440400402402.

It is a junction number, because it is equal to n+sod(n) for n = 20420400404399 and 20420400404408.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2976481 + ... + 7049839.

It is an arithmetic number, because the mean of its divisors is an integer number (1435821212250).

Almost surely, 2^{20420400404440} is an apocalyptic number.

20420400404440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20420400404440 is an abundant number, since it is smaller than the sum of its proper divisors (25525878387560).

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

20420400404440 is a wasteful number, since it uses less digits than its factorization.

20420400404440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4198699 (or 4198695 counting only the distinct ones).

The product of its (nonzero) digits is 16384, while the sum is 28.

Adding to 20420400404440 its reverse (4440400402402), we get a palindrome (24860800806842).

The spelling of 20420400404440 in words is "twenty trillion, four hundred twenty billion, four hundred million, four hundred four thousand, four hundred forty".