20401320420 has 192 divisors, whose sum is σ = 68453360640. Its totient is φ = 5014503936.

The previous prime is 20401320419. The next prime is 20401320431. The reversal of 20401320420 is 2402310402.

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 = 20401320393 and 20401320402.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5986357 + ... + 5989763.

It is an arithmetic number, because the mean of its divisors is an integer number (356527920).

Almost surely, 2^20401320420 is an apocalyptic number.

20401320420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20401320420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34226680320).

20401320420 is an abundant number, since it is smaller than the sum of its proper divisors (48052040220).

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

20401320420 is a wasteful number, since it uses less digits than its factorization.

20401320420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4291 (or 4283 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

Adding to 20401320420 its reverse (2402310402), we get a palindrome (22803630822).

The spelling of 20401320420 in words is "twenty billion, four hundred one million, three hundred twenty thousand, four hundred twenty".