31800105 has 12 divisors (see below), whose sum is σ = 55120260. Its totient is φ = 16960032.

The previous prime is 31800103. The next prime is 31800113. The reversal of 31800105 is 50100813.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 12299049 + 19501056 = 3507^2 + 4416^2 .

It is not a de Polignac number, because 31800105 - 2¹ = 31800103 is a prime.

It is a super-2 number, since 2×31800105² = 2022493356022050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31800101) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 353290 + ... + 353379.

It is an arithmetic number, because the mean of its divisors is an integer number (4593355).

Almost surely, 2^31800105 is an apocalyptic number.

It is an amenable number.

31800105 is a deficient number, since it is larger than the sum of its proper divisors (23320155).

31800105 is a wasteful number, since it uses less digits than its factorization.

31800105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 706680 (or 706677 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 31800105 is about 5639.1581818566. The cubic root of 31800105 is about 316.8177592298.

Adding to 31800105 its reverse (50100813), we get a palindrome (81900918).

The spelling of 31800105 in words is "thirty-one million, eight hundred thousand, one hundred five".