31001161 has 2 divisors, whose sum is σ = 31001162. Its totient is φ = 31001160.

The previous prime is 31001143. The next prime is 31001221. The reversal of 31001161 is 16110013.

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., 30735936 + 265225 = 5544^2 + 515^2 .

It is an emirp because it is prime and its reverse (16110013) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31001161 - 2⁹ = 31000649 is a prime.

It is a super-2 number, since 2×31001161² = 1922143966695842, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (31001111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15500580 + 15500581.

It is an arithmetic number, because the mean of its divisors is an integer number (15500581).

Almost surely, 2^31001161 is an apocalyptic number.

It is an amenable number.

31001161 is a deficient number, since it is larger than the sum of its proper divisors (1).

31001161 is an equidigital number, since it uses as much as digits as its factorization.

31001161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18, while the sum is 13.

The square root of 31001161 is about 5567.8686227317. The cubic root of 31001161 is about 314.1419868493.

Adding to 31001161 its reverse (16110013), we get a palindrome (47111174).

The spelling of 31001161 in words is "thirty-one million, one thousand, one hundred sixty-one".