21011121210112 has 216 divisors, whose sum is σ = 47358007796736. Its totient is φ = 9226480896000.

The previous prime is 21011121210103. The next prime is 21011121210161. The reversal of 21011121210112 is 21101212111012.

It is a Harshad number since it is a multiple of its sum of digits (16).

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, 1642642437 + ... + 1642655227.

It is an arithmetic number, because the mean of its divisors is an integer number (219250036096).

Almost surely, 2^{21011121210112} is an apocalyptic number.

21011121210112 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21011121210112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23679003898368).

21011121210112 is an abundant number, since it is smaller than the sum of its proper divisors (26346886586624).

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

21011121210112 is a wasteful number, since it uses less digits than its factorization.

21011121210112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13487 (or 13442 counting only the distinct ones).

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

Adding to 21011121210112 its reverse (21101212111012), we get a palindrome (42112333321124).

The spelling of 21011121210112 in words is "twenty-one trillion, eleven billion, one hundred twenty-one million, two hundred ten thousand, one hundred twelve".