20421402100 has 144 divisors (see below), whose sum is σ = 49050360576. Its totient is φ = 7318080000.

The previous prime is 20421402097. The next prime is 20421402121. The reversal of 20421402100 is 120412402.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 44106469 + ... + 44106931.

It is an arithmetic number, because the mean of its divisors is an integer number (340627504).

Almost surely, 2^20421402100 is an apocalyptic number.

20421402100 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 20421402100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24525180288).

20421402100 is an abundant number, since it is smaller than the sum of its proper divisors (28628958476).

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

20421402100 is a wasteful number, since it uses less digits than its factorization.

20421402100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 986 (or 979 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 20421402100 its reverse (120412402), we get a palindrome (20541814502).

The spelling of 20421402100 in words is "twenty billion, four hundred twenty-one million, four hundred two thousand, one hundred".