20211220100 has 72 divisors (see below), whose sum is σ = 48457398528. Its totient is φ = 7278092800.

The previous prime is 20211220063. The next prime is 20211220147. The reversal of 20211220100 is 102211202.

It is a happy 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, 219356 + ... + 297555.

It is an arithmetic number, because the mean of its divisors is an integer number (673019424).

Almost surely, 2^20211220100 is an apocalyptic number.

20211220100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20211220100 is an abundant number, since it is smaller than the sum of its proper divisors (28246178428).

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

20211220100 is a wasteful number, since it uses less digits than its factorization.

20211220100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 516965 (or 516958 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 20211220100 its reverse (102211202), we get a palindrome (20313431302).

The spelling of 20211220100 in words is "twenty billion, two hundred eleven million, two hundred twenty thousand, one hundred".