71538391 has 2 divisors, whose sum is σ = 71538392. Its totient is φ = 71538390.

The previous prime is 71538377. The next prime is 71538403. The reversal of 71538391 is 19383517.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (19383517) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 71538391 - 2¹⁹ = 71014103 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 71538391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71538361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35769195 + 35769196.

It is an arithmetic number, because the mean of its divisors is an integer number (35769196).

Almost surely, 2^71538391 is an apocalyptic number.

71538391 is a deficient number, since it is larger than the sum of its proper divisors (1).

71538391 is an equidigital number, since it uses as much as digits as its factorization.

71538391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22680, while the sum is 37.

The square root of 71538391 is about 8458.0370654189. The cubic root of 71538391 is about 415.1257972535.

The spelling of 71538391 in words is "seventy-one million, five hundred thirty-eight thousand, three hundred ninety-one".