21101212112112 has 120 divisors (see below), whose sum is σ = 64423786600368. Its totient is φ = 6394192896000.

The previous prime is 21101212112089. The next prime is 21101212112129. The reversal of 21101212112112 is 21121121210112.

It is a happy number.

It is a super-2 number, since 2×21101212112112² (a number of 27 digits) contains 22 as substring.

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

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, 144852112 + ... + 144997712.

Almost surely, 2^{21101212112112} is an apocalyptic number.

21101212112112 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21101212112112 is an abundant number, since it is smaller than the sum of its proper divisors (43322574488256).

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

21101212112112 is a wasteful number, since it uses less digits than its factorization.

21101212112112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 237119 (or 237110 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 21101212112112 its reverse (21121121210112), we get a palindrome (42222333322224).

The spelling of 21101212112112 in words is "twenty-one trillion, one hundred one billion, two hundred twelve million, one hundred twelve thousand, one hundred twelve".