21121111101001 has 8 divisors (see below), whose sum is σ = 21131936208864. Its totient is φ = 21110287614240.

The previous prime is 21121111100977. The next prime is 21121111101029. The reversal of 21121111101001 is 10010111112112.

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

It is a cyclic number.

It is not a de Polignac number, because 21121111101001 - 2⁹ = 21121111100489 is a prime.

It is a super-2 number, since 2×21121111101001² (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 (21121111101031) 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, 26102166 + ... + 26899168.

It is an arithmetic number, because the mean of its divisors is an integer number (2641492026108).

Almost surely, 2^{21121111101001} is an apocalyptic number.

It is an amenable number.

21121111101001 is a deficient number, since it is larger than the sum of its proper divisors (10825107863).

21121111101001 is a wasteful number, since it uses less digits than its factorization.

21121111101001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 810551.

The product of its (nonzero) digits is 4, while the sum is 13.

Adding to 21121111101001 its reverse (10010111112112), we get a palindrome (31131222213113).

The spelling of 21121111101001 in words is "twenty-one trillion, one hundred twenty-one billion, one hundred eleven million, one hundred one thousand, one".