71563813 has 2 divisors, whose sum is σ = 71563814. Its totient is φ = 71563812.

The previous prime is 71563801. The next prime is 71563831. The reversal of 71563813 is 31836517.

Together with next prime (71563831) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60949249 + 10614564 = 7807^2 + 3258^2 .

It is a cyclic number.

It is not a de Polignac number, because 71563813 - 2¹⁷ = 71432741 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71563313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35781906 + 35781907.

It is an arithmetic number, because the mean of its divisors is an integer number (35781907).

Almost surely, 2^71563813 is an apocalyptic number.

It is an amenable number.

71563813 is a deficient number, since it is larger than the sum of its proper divisors (1).

71563813 is an equidigital number, since it uses as much as digits as its factorization.

71563813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15120, while the sum is 34.

The square root of 71563813 is about 8459.5397628949. The cubic root of 71563813 is about 415.1749646913.

The spelling of 71563813 in words is "seventy-one million, five hundred sixty-three thousand, eight hundred thirteen".