71639297 has 4 divisors (see below), whose sum is σ = 71799300. Its totient is φ = 71479296.

The previous prime is 71639279. The next prime is 71639299. The reversal of 71639297 is 79293617.

It is a happy number.

It is a Cunningham number, because it is equal to 92⁴+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 43771456 + 27867841 = 6616^2 + 5279^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71639297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71639299) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 79328 + ... + 80225.

It is an arithmetic number, because the mean of its divisors is an integer number (17949825).

Almost surely, 2^71639297 is an apocalyptic number.

It is an amenable number.

71639297 is a deficient number, since it is larger than the sum of its proper divisors (160003).

71639297 is a wasteful number, since it uses less digits than its factorization.

71639297 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160002.

The product of its digits is 142884, while the sum is 44.

The square root of 71639297 is about 8464.0000590737. Note that the first 4 decimals coincide. The cubic root of 71639297 is about 415.3208859961.

The spelling of 71639297 in words is "seventy-one million, six hundred thirty-nine thousand, two hundred ninety-seven".