31137643 has 2 divisors, whose sum is σ = 31137644. Its totient is φ = 31137642.

The previous prime is 31137571. The next prime is 31137661. The reversal of 31137643 is 34673113.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (34673113) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31137643 - 2⁹ = 31137131 is a prime.

It is not a weakly prime, because it can be changed into another prime (31137443) 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, 15568821 + 15568822.

It is an arithmetic number, because the mean of its divisors is an integer number (15568822).

Almost surely, 2^31137643 is an apocalyptic number.

31137643 is a deficient number, since it is larger than the sum of its proper divisors (1).

31137643 is an equidigital number, since it uses as much as digits as its factorization.

31137643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4536, while the sum is 28.

The square root of 31137643 is about 5580.1113788167. Note that the first 3 decimals coincide. The cubic root of 31137643 is about 314.6023132836.

The spelling of 31137643 in words is "thirty-one million, one hundred thirty-seven thousand, six hundred forty-three".