20121100215420 has 48 divisors (see below), whose sum is σ = 56430096992640. Its totient is φ = 5356958496576.

The previous prime is 20121100215413. The next prime is 20121100215467. The reversal of 20121100215420 is 2451200112102.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 270844662 + ... + 270918941.

It is an arithmetic number, because the mean of its divisors is an integer number (1175627020680).

Almost surely, 2^{20121100215420} is an apocalyptic number.

20121100215420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20121100215420 is an abundant number, since it is smaller than the sum of its proper divisors (36308996777220).

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

20121100215420 is a wasteful number, since it uses less digits than its factorization.

20121100215420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 541764234 (or 541764232 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 21.

Adding to 20121100215420 its reverse (2451200112102), we get a palindrome (22572300327522).

The spelling of 20121100215420 in words is "twenty trillion, one hundred twenty-one billion, one hundred million, two hundred fifteen thousand, four hundred twenty".