21002122220100 has 144 divisors (see below), whose sum is σ = 72466453183488. Its totient is φ = 4591768325760.

The previous prime is 21002122220083. The next prime is 21002122220117. The reversal of 21002122220100 is 102222120012.

It is an interprime number because it is at equal distance from previous prime (21002122220083) and next prime (21002122220117).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21002122220100.

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, 217364974 + ... + 217461573.

Almost surely, 2^{21002122220100} is an apocalyptic number.

21002122220100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21002122220100 is an abundant number, since it is smaller than the sum of its proper divisors (51464330963388).

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

21002122220100 is a wasteful number, since it uses less digits than its factorization.

21002122220100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 434826594 (or 434826587 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21002122220100 its reverse (102222120012), we get a palindrome (21104344340112).

The spelling of 21002122220100 in words is "twenty-one trillion, two billion, one hundred twenty-two million, two hundred twenty thousand, one hundred".