71945813 has 2 divisors, whose sum is σ = 71945814. Its totient is φ = 71945812.

The previous prime is 71945759. The next prime is 71945827. The reversal of 71945813 is 31854917.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42276004 + 29669809 = 6502^2 + 5447^2 .

It is an emirp because it is prime and its reverse (31854917) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 71945813 - 2⁶ = 71945749 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 (71945843) 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, 35972906 + 35972907.

It is an arithmetic number, because the mean of its divisors is an integer number (35972907).

Almost surely, 2^71945813 is an apocalyptic number.

It is an amenable number.

71945813 is a deficient number, since it is larger than the sum of its proper divisors (1).

71945813 is an equidigital number, since it uses as much as digits as its factorization.

71945813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 38.

The square root of 71945813 is about 8482.0877736557. The cubic root of 71945813 is about 415.9123740642.

The spelling of 71945813 in words is "seventy-one million, nine hundred forty-five thousand, eight hundred thirteen".