31720103 has 2 divisors, whose sum is σ = 31720104. Its totient is φ = 31720102.

The previous prime is 31720049. The next prime is 31720121. The reversal of 31720103 is 30102713.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31720103 - 2¹⁴ = 31703719 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31720133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15860051 + 15860052.

It is an arithmetic number, because the mean of its divisors is an integer number (15860052).

Almost surely, 2^31720103 is an apocalyptic number.

31720103 is a deficient number, since it is larger than the sum of its proper divisors (1).

31720103 is an equidigital number, since it uses as much as digits as its factorization.

31720103 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 126, while the sum is 17.

The square root of 31720103 is about 5632.0602802172. The cubic root of 31720103 is about 316.5518550853.

Adding to 31720103 its reverse (30102713), we get a palindrome (61822816).

The spelling of 31720103 in words is "thirty-one million, seven hundred twenty thousand, one hundred three".