21011222220100 has 72 divisors (see below), whose sum is σ = 52114147050560. Its totient is φ = 7202974446720.

The previous prime is 21011222220077. The next prime is 21011222220103. The reversal of 21011222220100 is 102222211012.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21011222220103) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3973327 + ... + 7603273.

Almost surely, 2^{21011222220100} is an apocalyptic number.

21011222220100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21011222220100 is an abundant number, since it is smaller than the sum of its proper divisors (31102924830460).

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

21011222220100 is a wasteful number, since it uses less digits than its factorization.

21011222220100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3638237 (or 3638230 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21011222220100 its reverse (102222211012), we get a palindrome (21113444431112).

The spelling of 21011222220100 in words is "twenty-one trillion, eleven billion, two hundred twenty-two million, two hundred twenty thousand, one hundred".