31111013 has 2 divisors, whose sum is σ = 31111014. Its totient is φ = 31111012.

The previous prime is 31111009. The next prime is 31111057. The reversal of 31111013 is 31011113.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26646244 + 4464769 = 5162^2 + 2113^2 .

It is a cyclic number.

It is not a de Polignac number, because 31111013 - 2² = 31111009 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31110985 and 31111003.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31111313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15555506 + 15555507.

It is an arithmetic number, because the mean of its divisors is an integer number (15555507).

Almost surely, 2^31111013 is an apocalyptic number.

It is an amenable number.

31111013 is a deficient number, since it is larger than the sum of its proper divisors (1).

31111013 is an equidigital number, since it uses as much as digits as its factorization.

31111013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9, while the sum is 11.

The square root of 31111013 is about 5577.7247153297. The cubic root of 31111013 is about 314.5126014078.

Adding to 31111013 its reverse (31011113), we get a palindrome (62122126).

The spelling of 31111013 in words is "thirty-one million, one hundred eleven thousand, thirteen".