31212103121081 has 2 divisors, whose sum is σ = 31212103121082. Its totient is φ = 31212103121080.

The previous prime is 31212103121047. The next prime is 31212103121113. The reversal of 31212103121081 is 18012130121213.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20165892516025 + 11046210605056 = 4490645^2 + 3323584^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31212103121081 is a prime.

It is a super-2 number, since 2×31212103121081² (a number of 28 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 31212103121081.

It is not a weakly prime, because it can be changed into another prime (31212103121581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15606051560540 + 15606051560541.

It is an arithmetic number, because the mean of its divisors is an integer number (15606051560541).

Almost surely, 2^{31212103121081} is an apocalyptic number.

It is an amenable number.

31212103121081 is a deficient number, since it is larger than the sum of its proper divisors (1).

31212103121081 is an equidigital number, since it uses as much as digits as its factorization.

31212103121081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 26.

Adding to 31212103121081 its reverse (18012130121213), we get a palindrome (49224233242294).

The spelling of 31212103121081 in words is "thirty-one trillion, two hundred twelve billion, one hundred three million, one hundred twenty-one thousand, eighty-one".