31012213 has 2 divisors, whose sum is σ = 31012214. Its totient is φ = 31012212.

The previous prime is 31012193. The next prime is 31012231. The reversal of 31012213 is 31221013.

Together with next prime (31012231) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29181604 + 1830609 = 5402^2 + 1353^2 .

It is a cyclic number.

It is not a de Polignac number, because 31012213 - 2¹⁷ = 30881141 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31012193 and 31012202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31012243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15506106 + 15506107.

It is an arithmetic number, because the mean of its divisors is an integer number (15506107).

Almost surely, 2^31012213 is an apocalyptic number.

It is an amenable number.

31012213 is a deficient number, since it is larger than the sum of its proper divisors (1).

31012213 is an equidigital number, since it uses as much as digits as its factorization.

31012213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 31012213 is about 5568.8610146061. The cubic root of 31012213 is about 314.1793132442.

Adding to 31012213 its reverse (31221013), we get a palindrome (62233226).

The spelling of 31012213 in words is "thirty-one million, twelve thousand, two hundred thirteen".