20021220210100 has 72 divisors (see below), whose sum is σ = 43501133046168. Its totient is φ = 7998336614400.

The previous prime is 20021220210073. The next prime is 20021220210127. The reversal of 20021220210100 is 101202212002.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20021220210073) and next prime (20021220210127).

It can be written as a sum of positive squares in 12 ways, for example, as 14651164803856 + 5370055406244 = 3827684^2 + 2317338^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1327923762 + ... + 1327938838.

It is an arithmetic number, because the mean of its divisors is an integer number (604182403419).

Almost surely, 2^{20021220210100} is an apocalyptic number.

20021220210100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20021220210100 is an abundant number, since it is smaller than the sum of its proper divisors (23479912836068).

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

20021220210100 is a wasteful number, since it uses less digits than its factorization.

20021220210100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31045 (or 31038 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 20021220210100 its reverse (101202212002), we get a palindrome (20122422422102).

The spelling of 20021220210100 in words is "twenty trillion, twenty-one billion, two hundred twenty million, two hundred ten thousand, one hundred".