71439649 has 2 divisors, whose sum is σ = 71439650. Its totient is φ = 71439648.

The previous prime is 71439647. The next prime is 71439653. The reversal of 71439649 is 94693417.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 62094400 + 9345249 = 7880^2 + 3057^2 .

It is a cyclic number.

It is not a de Polignac number, because 71439649 - 2¹ = 71439647 is a prime.

Together with 71439647, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (71439647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35719824 + 35719825.

It is an arithmetic number, because the mean of its divisors is an integer number (35719825).

Almost surely, 2^71439649 is an apocalyptic number.

It is an amenable number.

71439649 is a deficient number, since it is larger than the sum of its proper divisors (1).

71439649 is an equidigital number, since it uses as much as digits as its factorization.

71439649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 163296, while the sum is 43.

The square root of 71439649 is about 8452.1978798417. The cubic root of 71439649 is about 414.9347146540.

The spelling of 71439649 in words is "seventy-one million, four hundred thirty-nine thousand, six hundred forty-nine".