21121101021012 has 192 divisors, whose sum is σ = 52511455180800. Its totient is φ = 6593021360640.

The previous prime is 21121101020983. The next prime is 21121101021043. The reversal of 21121101021012 is 21012010112112.

It is a happy number.

It is a super-2 number, since 2×21121101021012² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21121101020982 and 21121101021000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4777446562 + ... + 4777450982.

It is an arithmetic number, because the mean of its divisors is an integer number (273497162400).

Almost surely, 2^{21121101021012} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21121101021012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26255727590400).

21121101021012 is an abundant number, since it is smaller than the sum of its proper divisors (31390354159788).

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

21121101021012 is a wasteful number, since it uses less digits than its factorization.

21121101021012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5646 (or 5644 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21121101021012 its reverse (21012010112112), we get a palindrome (42133111133124).

The spelling of 21121101021012 in words is "twenty-one trillion, one hundred twenty-one billion, one hundred one million, twenty-one thousand, twelve".