213131122031 has 2 divisors, whose sum is σ = 213131122032. Its totient is φ = 213131122030.

The previous prime is 213131122027. The next prime is 213131122037. The reversal of 213131122031 is 130221131312.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 213131122031 - 2² = 213131122027 is a prime.

It is a super-2 number, since 2×213131122031² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 213131121994 and 213131122012.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213131122037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106565561015 + 106565561016.

It is an arithmetic number, because the mean of its divisors is an integer number (106565561016).

Almost surely, 2^213131122031 is an apocalyptic number.

213131122031 is a deficient number, since it is larger than the sum of its proper divisors (1).

213131122031 is an equidigital number, since it uses as much as digits as its factorization.

213131122031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 20.

Adding to 213131122031 its reverse (130221131312), we get a palindrome (343352253343).

The spelling of 213131122031 in words is "two hundred thirteen billion, one hundred thirty-one million, one hundred twenty-two thousand, thirty-one".