21121110101001 has 16 divisors (see below), whose sum is σ = 28175315187200. Its totient is φ = 14073823830528.

The previous prime is 21121110100933. The next prime is 21121110101011. The reversal of 21121110101001 is 10010101112112.

It is not a de Polignac number, because 21121110101001 - 2²⁵ = 21121076546569 is a prime.

It is a super-2 number, since 2×21121110101001² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21121110101011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 67686105 + ... + 67997433.

It is an arithmetic number, because the mean of its divisors is an integer number (1760957199200).

Almost surely, 2^{21121110101001} is an apocalyptic number.

It is an amenable number.

21121110101001 is a deficient number, since it is larger than the sum of its proper divisors (7054205086199).

21121110101001 is a wasteful number, since it uses less digits than its factorization.

21121110101001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322368.

The product of its (nonzero) digits is 4, while the sum is 12.

Adding to 21121110101001 its reverse (10010101112112), we get a palindrome (31131211213113).

The spelling of 21121110101001 in words is "twenty-one trillion, one hundred twenty-one billion, one hundred ten million, one hundred one thousand, one".