31121315200109 has 2 divisors, whose sum is σ = 31121315200110. Its totient is φ = 31121315200108.

The previous prime is 31121315200049. The next prime is 31121315200111. The reversal of 31121315200109 is 90100251312113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30269220052009 + 852095148100 = 5501747^2 + 923090^2 .

It is a cyclic number.

It is not a de Polignac number, because 31121315200109 - 2²⁰ = 31121314151533 is a prime.

It is a super-2 number, since 2×31121315200109² (a number of 28 digits) contains 22 as substring.

Together with 31121315200111, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31121315200009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15560657600054 + 15560657600055.

It is an arithmetic number, because the mean of its divisors is an integer number (15560657600055).

Almost surely, 2^{31121315200109} is an apocalyptic number.

It is an amenable number.

31121315200109 is a deficient number, since it is larger than the sum of its proper divisors (1).

31121315200109 is an equidigital number, since it uses as much as digits as its factorization.

31121315200109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1620, while the sum is 29.

The spelling of 31121315200109 in words is "thirty-one trillion, one hundred twenty-one billion, three hundred fifteen million, two hundred thousand, one hundred nine".