31221211051 has 2 divisors, whose sum is σ = 31221211052. Its totient is φ = 31221211050.

The previous prime is 31221211013. The next prime is 31221211097. The reversal of 31221211051 is 15011212213.

It is a weak prime.

It is an emirp because it is prime and its reverse (15011212213) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31221211051 - 2²⁹ = 30684340139 is a prime.

It is not a weakly prime, because it can be changed into another prime (31221211951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15610605525 + 15610605526.

It is an arithmetic number, because the mean of its divisors is an integer number (15610605526).

Almost surely, 2^31221211051 is an apocalyptic number.

31221211051 is a deficient number, since it is larger than the sum of its proper divisors (1).

31221211051 is an equidigital number, since it uses as much as digits as its factorization.

31221211051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 120, while the sum is 19.

Adding to 31221211051 its reverse (15011212213), we get a palindrome (46232423264).

The spelling of 31221211051 in words is "thirty-one billion, two hundred twenty-one million, two hundred eleven thousand, fifty-one".