31438189 has 2 divisors, whose sum is σ = 31438190. Its totient is φ = 31438188.

The previous prime is 31438181. The next prime is 31438213. The reversal of 31438189 is 98183413.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21622500 + 9815689 = 4650^2 + 3133^2 .

It is a cyclic number.

It is not a de Polignac number, because 31438189 - 2³ = 31438181 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31438181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15719094 + 15719095.

It is an arithmetic number, because the mean of its divisors is an integer number (15719095).

Almost surely, 2^31438189 is an apocalyptic number.

It is an amenable number.

31438189 is a deficient number, since it is larger than the sum of its proper divisors (1).

31438189 is an equidigital number, since it uses as much as digits as its factorization.

31438189 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 37.

The square root of 31438189 is about 5606.9768146480. The cubic root of 31438189 is about 315.6112729252.

It can be divided in two parts, 314 and 38189, that added together give a triangular number (38503 = T₂₇₇).

The spelling of 31438189 in words is "thirty-one million, four hundred thirty-eight thousand, one hundred eighty-nine".