71988649 has 2 divisors, whose sum is σ = 71988650. Its totient is φ = 71988648.

The previous prime is 71988641. The next prime is 71988677. The reversal of 71988649 is 94688917.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 43824400 + 28164249 = 6620^2 + 5307^2 .

It is an emirp because it is prime and its reverse (94688917) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 71988649 - 2³ = 71988641 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 71988596 and 71988605.

It is not a weakly prime, because it can be changed into another prime (71988641) 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, 35994324 + 35994325.

It is an arithmetic number, because the mean of its divisors is an integer number (35994325).

Almost surely, 2^71988649 is an apocalyptic number.

It is an amenable number.

71988649 is a deficient number, since it is larger than the sum of its proper divisors (1).

71988649 is an equidigital number, since it uses as much as digits as its factorization.

71988649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 870912, while the sum is 52.

The square root of 71988649 is about 8484.6124837850. The cubic root of 71988649 is about 415.9949013952.

The spelling of 71988649 in words is "seventy-one million, nine hundred eighty-eight thousand, six hundred forty-nine".