31125161 has 2 divisors, whose sum is σ = 31125162. Its totient is φ = 31125160.

The previous prime is 31125121. The next prime is 31125203. The reversal of 31125161 is 16152113.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 29767936 + 1357225 = 5456^2 + 1165^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31125161 is a prime.

It is not a weakly prime, because it can be changed into another prime (31125121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15562580 + 15562581.

It is an arithmetic number, because the mean of its divisors is an integer number (15562581).

Almost surely, 2^31125161 is an apocalyptic number.

It is an amenable number.

31125161 is a deficient number, since it is larger than the sum of its proper divisors (1).

31125161 is an equidigital number, since it uses as much as digits as its factorization.

31125161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 180, while the sum is 20.

The square root of 31125161 is about 5578.9928302517. The cubic root of 31125161 is about 314.5602699503.

Adding to 31125161 its reverse (16152113), we get a palindrome (47277274).

The spelling of 31125161 in words is "thirty-one million, one hundred twenty-five thousand, one hundred sixty-one".