21001012101121 has 16 divisors (see below), whose sum is σ = 22850002844928. Its totient is φ = 19185388992000.

The previous prime is 21001012101101. The next prime is 21001012101149. The reversal of 21001012101121 is 12110121010012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21001012101121 - 2⁵ = 21001012101089 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21001012101101) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 122118846 + ... + 122290696.

It is an arithmetic number, because the mean of its divisors is an integer number (1428125177808).

Almost surely, 2^{21001012101121} is an apocalyptic number.

It is an amenable number.

21001012101121 is a deficient number, since it is larger than the sum of its proper divisors (1848990743807).

21001012101121 is a wasteful number, since it uses less digits than its factorization.

21001012101121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268872.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21001012101121 its reverse (12110121010012), we get a palindrome (33111133111133).

The spelling of 21001012101121 in words is "twenty-one trillion, one billion, twelve million, one hundred one thousand, one hundred twenty-one".