213131121031 has 2 divisors, whose sum is σ = 213131121032. Its totient is φ = 213131121030.

The previous prime is 213131121013. The next prime is 213131121067. The reversal of 213131121031 is 130121131312.

Together with previous prime (213131121013) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 213131121031 - 2⁹ = 213131120519 is a prime.

It is a super-2 number, since 2×213131121031² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213131121131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106565560515 + 106565560516.

It is an arithmetic number, because the mean of its divisors is an integer number (106565560516).

Almost surely, 2^213131121031 is an apocalyptic number.

213131121031 is a deficient number, since it is larger than the sum of its proper divisors (1).

213131121031 is an equidigital number, since it uses as much as digits as its factorization.

213131121031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108, while the sum is 19.

Adding to 213131121031 its reverse (130121131312), we get a palindrome (343252252343).

The spelling of 213131121031 in words is "two hundred thirteen billion, one hundred thirty-one million, one hundred twenty-one thousand, thirty-one".