21012122121012 has 144 divisors (see below), whose sum is σ = 58931195319360. Its totient is φ = 6258688128000.

The previous prime is 21012122120987. The next prime is 21012122121091.

21012122121012 is a `hidden beast` number, since 210 + 1 + 21 + 221 + 210 + 1 + 2 = 666.

21012122121012 is nontrivially palindromic in base 10.

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 47 ways as a sum of consecutive naturals, for example, 231281548 + ... + 231372380.

It is an arithmetic number, because the mean of its divisors is an integer number (409244411940).

Almost surely, 2^{21012122121012} is an apocalyptic number.

21012122121012 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 21012122121012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29465597659680).

21012122121012 is an abundant number, since it is smaller than the sum of its proper divisors (37919073198348).

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

21012122121012 is a wasteful number, since it uses less digits than its factorization.

21012122121012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100814 (or 100809 counting only the distinct ones).

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

It can be divided in two parts, 2101212 and 2121012, that added together give a palindrome (4222224).

The spelling of 21012122121012 in words is "twenty-one trillion, twelve billion, one hundred twenty-two million, one hundred twenty-one thousand, twelve".