31103021 has 2 divisors, whose sum is σ = 31103022. Its totient is φ = 31103020.

The previous prime is 31102999. The next prime is 31103029. The reversal of 31103021 is 12030113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30680521 + 422500 = 5539^2 + 650^2 .

It is a cyclic number.

It is not a de Polignac number, because 31103021 - 2⁶ = 31102957 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 31102993 and 31103011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31103029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15551510 + 15551511.

It is an arithmetic number, because the mean of its divisors is an integer number (15551511).

Almost surely, 2^31103021 is an apocalyptic number.

It is an amenable number.

31103021 is a deficient number, since it is larger than the sum of its proper divisors (1).

31103021 is an equidigital number, since it uses as much as digits as its factorization.

31103021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18, while the sum is 11.

The square root of 31103021 is about 5577.0082481560. The cubic root of 31103021 is about 314.4856677516.

Adding to 31103021 its reverse (12030113), we get a palindrome (43133134).

The spelling of 31103021 in words is "thirty-one million, one hundred three thousand, twenty-one".