131211121021 has 4 divisors (see below), whose sum is σ = 131212184832. Its totient is φ = 131210057212.

The previous prime is 131211121009. The next prime is 131211121039. The reversal of 131211121021 is 120121112131.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-131211121021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 131211120986 and 131211121004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131211121001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 318301 + ... + 603106.

It is an arithmetic number, because the mean of its divisors is an integer number (32803046208).

Almost surely, 2^131211121021 is an apocalyptic number.

It is an amenable number.

131211121021 is a deficient number, since it is larger than the sum of its proper divisors (1063811).

131211121021 is an equidigital number, since it uses as much as digits as its factorization.

131211121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1063810.

The product of its (nonzero) digits is 24, while the sum is 16.

Adding to 131211121021 its reverse (120121112131), we get a palindrome (251332233152).

The spelling of 131211121021 in words is "one hundred thirty-one billion, two hundred eleven million, one hundred twenty-one thousand, twenty-one".