31009105081 has 2 divisors, whose sum is σ = 31009105082. Its totient is φ = 31009105080.

The previous prime is 31009105063. The next prime is 31009105091. The reversal of 31009105081 is 18050190013.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25869505600 + 5139599481 = 160840^2 + 71691^2 .

It is an emirp because it is prime and its reverse (18050190013) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31009105081 - 2¹⁵ = 31009072313 is a prime.

It is a super-2 number, since 2×31009105081² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (31009105091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15504552540 + 15504552541.

It is an arithmetic number, because the mean of its divisors is an integer number (15504552541).

Almost surely, 2^31009105081 is an apocalyptic number.

It is an amenable number.

31009105081 is a deficient number, since it is larger than the sum of its proper divisors (1).

31009105081 is an equidigital number, since it uses as much as digits as its factorization.

31009105081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 28.

Adding to 31009105081 its reverse (18050190013), we get a palindrome (49059295094).

The spelling of 31009105081 in words is "thirty-one billion, nine million, one hundred five thousand, eighty-one".