71995909 has 2 divisors, whose sum is σ = 71995910. Its totient is φ = 71995908.

The previous prime is 71995849. The next prime is 71995933. The reversal of 71995909 is 90959917.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66341025 + 5654884 = 8145^2 + 2378^2 .

It is a cyclic number.

It is not a de Polignac number, because 71995909 - 2⁹ = 71995397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71995109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35997954 + 35997955.

It is an arithmetic number, because the mean of its divisors is an integer number (35997955).

Almost surely, 2^71995909 is an apocalyptic number.

It is an amenable number.

71995909 is a deficient number, since it is larger than the sum of its proper divisors (1).

71995909 is an equidigital number, since it uses as much as digits as its factorization.

71995909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 229635, while the sum is 49.

The square root of 71995909 is about 8485.0403063274. The cubic root of 71995909 is about 416.0088851807.

The spelling of 71995909 in words is "seventy-one million, nine hundred ninety-five thousand, nine hundred nine".