31540189 has 2 divisors, whose sum is σ = 31540190. Its totient is φ = 31540188.

The previous prime is 31540181. The next prime is 31540207. The reversal of 31540189 is 98104513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17724100 + 13816089 = 4210^2 + 3717^2 .

It is a cyclic number.

It is not a de Polignac number, because 31540189 - 2³ = 31540181 is a prime.

It is equal to p_1947118 and since 31540189 and 1947118 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31540189.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31540181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15770094 + 15770095.

It is an arithmetic number, because the mean of its divisors is an integer number (15770095).

Almost surely, 2^31540189 is an apocalyptic number.

It is an amenable number.

31540189 is a deficient number, since it is larger than the sum of its proper divisors (1).

31540189 is an equidigital number, since it uses as much as digits as its factorization.

31540189 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 31540189 is about 5616.0652595923. The cubic root of 31540189 is about 315.9522340075.

It can be divided in two parts, 315 and 40189, that added together give a palindrome (40504).

The spelling of 31540189 in words is "thirty-one million, five hundred forty thousand, one hundred eighty-nine".