31384513 has 2 divisors, whose sum is σ = 31384514. Its totient is φ = 31384512.

The previous prime is 31384487. The next prime is 31384517. The reversal of 31384513 is 31548313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17073424 + 14311089 = 4132^2 + 3783^2 .

It is an emirp because it is prime and its reverse (31548313) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31384513 - 2¹⁷ = 31253441 is a prime.

It is not a weakly prime, because it can be changed into another prime (31384517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15692256 + 15692257.

It is an arithmetic number, because the mean of its divisors is an integer number (15692257).

Almost surely, 2^31384513 is an apocalyptic number.

It is an amenable number.

31384513 is a deficient number, since it is larger than the sum of its proper divisors (1).

31384513 is an equidigital number, since it uses as much as digits as its factorization.

31384513 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4320, while the sum is 28.

The square root of 31384513 is about 5602.1882331817. The cubic root of 31384513 is about 315.4315509411.

The spelling of 31384513 in words is "thirty-one million, three hundred eighty-four thousand, five hundred thirteen".