31355145 has 24 divisors (see below), whose sum is σ = 54966600. Its totient is φ = 16532736.

The previous prime is 31355143. The next prime is 31355161. The reversal of 31355145 is 54155313.

It can be written as a sum of positive squares in 4 ways, for example, as 84681 + 31270464 = 291^2 + 5592^2 .

It is not a de Polignac number, because 31355145 - 2¹ = 31355143 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31355143) 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 23 ways as a sum of consecutive naturals, for example, 91 + ... + 7919.

It is an arithmetic number, because the mean of its divisors is an integer number (2290275).

Almost surely, 2^31355145 is an apocalyptic number.

It is an amenable number.

31355145 is a deficient number, since it is larger than the sum of its proper divisors (23611455).

31355145 is a wasteful number, since it uses less digits than its factorization.

31355145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7929 (or 7926 counting only the distinct ones).

The product of its digits is 4500, while the sum is 27.

The square root of 31355145 is about 5599.5665010785. The cubic root of 31355145 is about 315.3331320729. Note that the first 3 decimals are identical.

The spelling of 31355145 in words is "thirty-one million, three hundred fifty-five thousand, one hundred forty-five".