31245161 has 4 divisors (see below), whose sum is σ = 31774800. Its totient is φ = 30715524.

The previous prime is 31245121. The next prime is 31245163. The reversal of 31245161 is 16154213.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16154213 = 179 ⋅90247.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31245161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31245163) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 264731 + ... + 264848.

It is an arithmetic number, because the mean of its divisors is an integer number (7943700).

Almost surely, 2^31245161 is an apocalyptic number.

It is an amenable number.

31245161 is a deficient number, since it is larger than the sum of its proper divisors (529639).

31245161 is an equidigital number, since it uses as much as digits as its factorization.

31245161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 529638.

The product of its digits is 720, while the sum is 23.

The square root of 31245161 is about 5589.7371136754. The cubic root of 31245161 is about 314.9640036132.

Adding to 31245161 its reverse (16154213), we get a palindrome (47399374).

The spelling of 31245161 in words is "thirty-one million, two hundred forty-five thousand, one hundred sixty-one".