21121311131121 has 16 divisors (see below), whose sum is σ = 28235979953280. Its totient is φ = 14043781113600.

The previous prime is 21121311131047. The next prime is 21121311131147. The reversal of 21121311131121 is 12113111312112.

It is not a de Polignac number, because 21121311131121 - 2²² = 21121306936817 is a prime.

It is a super-2 number, since 2×21121311131121² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21121311121121) 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, 826111 + ... + 6551723.

It is an arithmetic number, because the mean of its divisors is an integer number (1764748747080).

Almost surely, 2^{21121311131121} is an apocalyptic number.

It is an amenable number.

21121311131121 is a deficient number, since it is larger than the sum of its proper divisors (7114668822159).

21121311131121 is a wasteful number, since it uses less digits than its factorization.

21121311131121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5728856.

The product of its digits is 72, while the sum is 21.

Adding to 21121311131121 its reverse (12113111312112), we get a palindrome (33234422443233).

The spelling of 21121311131121 in words is "twenty-one trillion, one hundred twenty-one billion, three hundred eleven million, one hundred thirty-one thousand, one hundred twenty-one".