71940013 has 2 divisors, whose sum is σ = 71940014. Its totient is φ = 71940012.

The previous prime is 71939993. The next prime is 71940017. The reversal of 71940013 is 31004917.

71940013 = 5997² + 5998².

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35976004 + 35964009 = 5998^2 + 5997^2 .

It is an emirp because it is prime and its reverse (31004917) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 71940013 - 2¹⁷ = 71808941 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 71940013.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71940017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35970006 + 35970007.

It is an arithmetic number, because the mean of its divisors is an integer number (35970007).

Almost surely, 2^71940013 is an apocalyptic number.

71940013 is the 5998-th centered square number.

It is an amenable number.

71940013 is a deficient number, since it is larger than the sum of its proper divisors (1).

71940013 is an equidigital number, since it uses as much as digits as its factorization.

71940013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 71940013 is about 8481.7458698077. The cubic root of 71940013 is about 415.9011973350.

The spelling of 71940013 in words is "seventy-one million, nine hundred forty thousand, thirteen".