21020201100100 has 36 divisors (see below), whose sum is σ = 45614966143684. Its totient is φ = 8407872190080.

The previous prime is 21020201100013. The next prime is 21020201100109. The reversal of 21020201100100 is 100110202012.

It can be written as a sum of positive squares in 6 ways, for example, as 360067203136 + 20660133896964 = 600056^2 + 4545342^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is not an unprimeable number, because it can be changed into a prime (21020201100109) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1486522 + ... + 6652078.

Almost surely, 2^{21020201100100} is an apocalyptic number.

21020201100100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21020201100100 is an abundant number, since it is smaller than the sum of its proper divisors (24594765043584).

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

21020201100100 is a wasteful number, since it uses less digits than its factorization.

21020201100100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5206264 (or 5206257 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21020201100100 its reverse (100110202012), we get a palindrome (21120311302112).

The spelling of 21020201100100 in words is "twenty-one trillion, twenty billion, two hundred one million, one hundred thousand, one hundred".