21001000121120 has 24 divisors (see below), whose sum is σ = 49614862786524. Its totient is φ = 8400400048384.

The previous prime is 21001000121111. The next prime is 21001000121209. The reversal of 21001000121120 is 2112100010012.

It can be written as a sum of positive squares in 2 ways, for example, as 19930760214544 + 1070239906576 = 4464388^2 + 1034524^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65628125219 + ... + 65628125538.

Almost surely, 2^{21001000121120} is an apocalyptic number.

21001000121120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001000121120 is an abundant number, since it is smaller than the sum of its proper divisors (28613862665404).

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

21001000121120 is a wasteful number, since it uses less digits than its factorization.

21001000121120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131256250772 (or 131256250764 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21001000121120 its reverse (2112100010012), we get a palindrome (23113100131132).

The spelling of 21001000121120 in words is "twenty-one trillion, one billion, one hundred twenty-one thousand, one hundred twenty".