20121031123 has 2 divisors, whose sum is σ = 20121031124. Its totient is φ = 20121031122.

The previous prime is 20121031121. The next prime is 20121031129. The reversal of 20121031123 is 32113012102.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20121031123 - 2¹ = 20121031121 is a prime.

It is a super-2 number, since 2×20121031123² (a number of 21 digits) contains 22 as substring.

Together with 20121031121, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 20121031097 and 20121031106.

It is not a weakly prime, because it can be changed into another prime (20121031121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060515561 + 10060515562.

It is an arithmetic number, because the mean of its divisors is an integer number (10060515562).

Almost surely, 2^20121031123 is an apocalyptic number.

20121031123 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121031123 is an equidigital number, since it uses as much as digits as its factorization.

20121031123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 20121031123 its reverse (32113012102), we get a palindrome (52234043225).

The spelling of 20121031123 in words is "twenty billion, one hundred twenty-one million, thirty-one thousand, one hundred twenty-three".