71942509 has 2 divisors, whose sum is σ = 71942510. Its totient is φ = 71942508.

The previous prime is 71942503. The next prime is 71942543. The reversal of 71942509 is 90524917.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64352484 + 7590025 = 8022^2 + 2755^2 .

It is a cyclic number.

It is not a de Polignac number, because 71942509 - 2³ = 71942501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71942501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35971254 + 35971255.

It is an arithmetic number, because the mean of its divisors is an integer number (35971255).

Almost surely, 2^71942509 is an apocalyptic number.

It is an amenable number.

71942509 is a deficient number, since it is larger than the sum of its proper divisors (1).

71942509 is an equidigital number, since it uses as much as digits as its factorization.

71942509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22680, while the sum is 37.

The square root of 71942509 is about 8481.8930080496. The cubic root of 71942509 is about 415.9060072562.

The spelling of 71942509 in words is "seventy-one million, nine hundred forty-two thousand, five hundred nine".