21001012001121 has 16 divisors (see below), whose sum is σ = 28013922222464. Its totient is φ = 13994389626624.

The previous prime is 21001012001111. The next prime is 21001012001149. The reversal of 21001012001121 is 12110021010012.

It is not a de Polignac number, because 21001012001121 - 2⁹ = 21001012000609 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21001012001097 and 21001012001106.

It is not an unprimeable number, because it can be changed into a prime (21001012001111) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 61304505 + ... + 61646121.

It is an arithmetic number, because the mean of its divisors is an integer number (1750870138904).

Almost surely, 2^{21001012001121} is an apocalyptic number.

It is an amenable number.

21001012001121 is a deficient number, since it is larger than the sum of its proper divisors (7012910221343).

21001012001121 is a wasteful number, since it uses less digits than its factorization.

21001012001121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 350760.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21001012001121 its reverse (12110021010012), we get a palindrome (33111033011133).

The spelling of 21001012001121 in words is "twenty-one trillion, one billion, twelve million, one thousand, one hundred twenty-one".