21201100010100 has 144 divisors (see below), whose sum is σ = 68164192143040. Its totient is φ = 5653080720000.

The previous prime is 21201100010059. The next prime is 21201100010117. The reversal of 21201100010100 is 101000110212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 27978819 + ... + 28726581.

Almost surely, 2^{21201100010100} is an apocalyptic number.

21201100010100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21201100010100 is an abundant number, since it is smaller than the sum of its proper divisors (46963092132940).

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

21201100010100 is a wasteful number, since it uses less digits than its factorization.

21201100010100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 758287 (or 758274 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 21201100010100 its reverse (101000110212), we get a palindrome (21302100120312).

The spelling of 21201100010100 in words is "twenty-one trillion, two hundred one billion, one hundred million, ten thousand, one hundred".