20121130921 has 2 divisors, whose sum is σ = 20121130922. Its totient is φ = 20121130920.

The previous prime is 20121130919. The next prime is 20121130949. The reversal of 20121130921 is 12903112102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16284567321 + 3836563600 = 127611^2 + 61940^2 .

It is a cyclic number.

It is not a de Polignac number, because 20121130921 - 2¹ = 20121130919 is a prime.

It is a super-3 number, since 3×20121130921³ (a number of 32 digits) contains 333 as substring.

Together with 20121130919, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 20121130892 and 20121130901.

It is not a weakly prime, because it can be changed into another prime (20121130721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060565460 + 10060565461.

It is an arithmetic number, because the mean of its divisors is an integer number (10060565461).

Almost surely, 2^20121130921 is an apocalyptic number.

It is an amenable number.

20121130921 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121130921 is an equidigital number, since it uses as much as digits as its factorization.

20121130921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 22.

The spelling of 20121130921 in words is "twenty billion, one hundred twenty-one million, one hundred thirty thousand, nine hundred twenty-one".