21001101122121 has 8 divisors (see below), whose sum is σ = 28004556482784. Its totient is φ = 13999189921440.

The previous prime is 21001101122101. The next prime is 21001101122159. The reversal of 21001101122121 is 12122110110012.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21001101122121 - 2¹¹ = 21001101120073 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21001101122121.

It is not an unprimeable number, because it can be changed into a prime (21001101122101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 386008260 + ... + 386062661.

It is an arithmetic number, because the mean of its divisors is an integer number (3500569560348).

Almost surely, 2^{21001101122121} is an apocalyptic number.

It is an amenable number.

21001101122121 is a deficient number, since it is larger than the sum of its proper divisors (7003455360663).

21001101122121 is an equidigital number, since it uses as much as digits as its factorization.

21001101122121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 772079991.

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

Adding to 21001101122121 its reverse (12122110110012), we get a palindrome (33123211232133).

The spelling of 21001101122121 in words is "twenty-one trillion, one billion, one hundred one million, one hundred twenty-two thousand, one hundred twenty-one".