71696509 has 2 divisors, whose sum is σ = 71696510. Its totient is φ = 71696508.

The previous prime is 71696503. The next prime is 71696551. The reversal of 71696509 is 90569617.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54804409 + 16892100 = 7403^2 + 4110^2 .

It is a cyclic number.

It is not a de Polignac number, because 71696509 - 2⁵ = 71696477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71696503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35848254 + 35848255.

It is an arithmetic number, because the mean of its divisors is an integer number (35848255).

Almost surely, 2^71696509 is an apocalyptic number.

It is an amenable number.

71696509 is a deficient number, since it is larger than the sum of its proper divisors (1).

71696509 is an equidigital number, since it uses as much as digits as its factorization.

71696509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 102060, while the sum is 43.

The square root of 71696509 is about 8467.3791104450. The cubic root of 71696509 is about 415.4314166544.

The spelling of 71696509 in words is "seventy-one million, six hundred ninety-six thousand, five hundred nine".