31012145 has 4 divisors (see below), whose sum is σ = 37214580. Its totient is φ = 24809712.

The previous prime is 31012141. The next prime is 31012169. The reversal of 31012145 is 54121013.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54121013 = 17 ⋅3183589.

It can be written as a sum of positive squares in 2 ways, for example, as 8392609 + 22619536 = 2897^2 + 4756^2 .

It is a cyclic number.

It is not a de Polignac number, because 31012145 - 2² = 31012141 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31012141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3101210 + ... + 3101219.

It is an arithmetic number, because the mean of its divisors is an integer number (9303645).

Almost surely, 2^31012145 is an apocalyptic number.

It is an amenable number.

31012145 is a deficient number, since it is larger than the sum of its proper divisors (6202435).

31012145 is an equidigital number, since it uses as much as digits as its factorization.

31012145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6202434.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 31012145 is about 5568.8549092251. The cubic root of 31012145 is about 314.1790836120.

Adding to 31012145 its reverse (54121013), we get a palindrome (85133158).

The spelling of 31012145 in words is "thirty-one million, twelve thousand, one hundred forty-five".