21112121121000 has 256 divisors, whose sum is σ = 81070546152960. Its totient is φ = 4454425497600.

The previous prime is 21112121120977. The next prime is 21112121121083. The reversal of 21112121121000 is 12112121112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 38393889 + ... + 38939888.

It is an arithmetic number, because the mean of its divisors is an integer number (316681820910).

Almost surely, 2^{21112121121000} is an apocalyptic number.

21112121121000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21112121121000 is an abundant number, since it is smaller than the sum of its proper divisors (59958425031960).

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

21112121121000 is a wasteful number, since it uses less digits than its factorization.

21112121121000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77333821 (or 77333807 counting only the distinct ones).

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

Adding to 21112121121000 its reverse (12112121112), we get a palindrome (21124233242112).

The spelling of 21112121121000 in words is "twenty-one trillion, one hundred twelve billion, one hundred twenty-one million, one hundred twenty-one thousand".