31440197 has 2 divisors, whose sum is σ = 31440198. Its totient is φ = 31440196.

The previous prime is 31440187. The next prime is 31440217. The reversal of 31440197 is 79104413.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26770276 + 4669921 = 5174^2 + 2161^2 .

It is an emirp because it is prime and its reverse (79104413) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31440197 - 2²² = 27245893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31440127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15720098 + 15720099.

It is an arithmetic number, because the mean of its divisors is an integer number (15720099).

Almost surely, 2^31440197 is an apocalyptic number.

It is an amenable number.

31440197 is a deficient number, since it is larger than the sum of its proper divisors (1).

31440197 is an equidigital number, since it uses as much as digits as its factorization.

31440197 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 31440197 is about 5607.1558744162. The cubic root of 31440197 is about 315.6179922896.

The spelling of 31440197 in words is "thirty-one million, four hundred forty thousand, one hundred ninety-seven".