21011011211121 has 16 divisors (see below), whose sum is σ = 28352539252800. Its totient is φ = 13838415933440.

The previous prime is 21011011211119. The next prime is 21011011211147. The reversal of 21011011211121 is 12111211011012.

It is a cyclic number.

It is not a de Polignac number, because 21011011211121 - 2¹ = 21011011211119 is a prime.

It is a super-2 number, since 2×21011011211121² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21011011211121.

It is not an unprimeable number, because it can be changed into a prime (21011011211161) 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, 23121841 + ... + 24013361.

It is an arithmetic number, because the mean of its divisors is an integer number (1772033703300).

Almost surely, 2^{21011011211121} is an apocalyptic number.

It is an amenable number.

21011011211121 is a deficient number, since it is larger than the sum of its proper divisors (7341528041679).

21011011211121 is an equidigital number, since it uses as much as digits as its factorization.

21011011211121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 986256.

The product of its (nonzero) digits is 8, while the sum is 15.

Adding to 21011011211121 its reverse (12111211011012), we get a palindrome (33122222222133).

The spelling of 21011011211121 in words is "twenty-one trillion, eleven billion, eleven million, two hundred eleven thousand, one hundred twenty-one".