21102112211220 has 72 divisors (see below), whose sum is σ = 65739733377864. Its totient is φ = 5475142626048.

The previous prime is 21102112211207. The next prime is 21102112211233. The reversal of 21102112211220 is 2211221120112.

21102112211220 is a `hidden beast` number, since 2 + 1 + 10 + 211 + 221 + 1 + 220 = 666.

It is an interprime number because it is at equal distance from previous prime (21102112211207) and next prime (21102112211233).

It can be written as a sum of positive squares in 4 ways, for example, as 610067220624 + 20492044990596 = 781068^2 + 4526814^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21102112211193 and 21102112211202.

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, 1584235999 + ... + 1584249318.

Almost surely, 2^{21102112211220} is an apocalyptic number.

21102112211220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21102112211220 is an abundant number, since it is smaller than the sum of its proper divisors (44637621166644).

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

21102112211220 is a wasteful number, since it uses less digits than its factorization.

21102112211220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3168485369 (or 3168485364 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21102112211220 its reverse (2211221120112), we get a palindrome (23313333331332).

The spelling of 21102112211220 in words is "twenty-one trillion, one hundred two billion, one hundred twelve million, two hundred eleven thousand, two hundred twenty".