71889709 has 2 divisors, whose sum is σ = 71889710. Its totient is φ = 71889708.

The previous prime is 71889667. The next prime is 71889721. The reversal of 71889709 is 90798817.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 71876484 + 13225 = 8478^2 + 115^2 .

It is a cyclic number.

It is not a de Polignac number, because 71889709 - 2⁷ = 71889581 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71889109) 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, 35944854 + 35944855.

It is an arithmetic number, because the mean of its divisors is an integer number (35944855).

Almost surely, 2^71889709 is an apocalyptic number.

It is an amenable number.

71889709 is a deficient number, since it is larger than the sum of its proper divisors (1).

71889709 is an equidigital number, since it uses as much as digits as its factorization.

71889709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 254016, while the sum is 49.

The square root of 71889709 is about 8478.7799240221. The cubic root of 71889709 is about 415.8042351981.

The spelling of 71889709 in words is "seventy-one million, eight hundred eighty-nine thousand, seven hundred nine".