71279909 has 2 divisors, whose sum is σ = 71279910. Its totient is φ = 71279908.

The previous prime is 71279899. The next prime is 71279911. The reversal of 71279909 is 90997217.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65966884 + 5313025 = 8122^2 + 2305^2 .

It is a cyclic number.

It is not a de Polignac number, because 71279909 - 2¹⁶ = 71214373 is a prime.

Together with 71279911, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 71279909.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71279959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35639954 + 35639955.

It is an arithmetic number, because the mean of its divisors is an integer number (35639955).

Almost surely, 2^71279909 is an apocalyptic number.

It is an amenable number.

71279909 is a deficient number, since it is larger than the sum of its proper divisors (1).

71279909 is an equidigital number, since it uses as much as digits as its factorization.

71279909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 71442, while the sum is 44.

The square root of 71279909 is about 8442.7429784401. The cubic root of 71279909 is about 414.6252173560.

The spelling of 71279909 in words is "seventy-one million, two hundred seventy-nine thousand, nine hundred nine".