71531065 has 8 divisors (see below), whose sum is σ = 86026248. Its totient is φ = 57098880.

The previous prime is 71531051. The next prime is 71531071. The reversal of 71531065 is 56013517.

It can be written as a sum of positive squares in 4 ways, for example, as 6953769 + 64577296 = 2637^2 + 8036^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 71531065 - 2²¹ = 69433913 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13212 + ... + 17821.

It is an arithmetic number, because the mean of its divisors is an integer number (10753281).

Almost surely, 2^71531065 is an apocalyptic number.

It is an amenable number.

71531065 is a deficient number, since it is larger than the sum of its proper divisors (14495183).

71531065 is a wasteful number, since it uses less digits than its factorization.

71531065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31499.

The product of its (nonzero) digits is 3150, while the sum is 28.

The square root of 71531065 is about 8457.6039751220. The cubic root of 71531065 is about 415.1116262358. Note that the first 3 decimals are identical.

The spelling of 71531065 in words is "seventy-one million, five hundred thirty-one thousand, sixty-five".