71531321 has 8 divisors (see below), whose sum is σ = 73409664. Its totient is φ = 69667920.

The previous prime is 71531303. The next prime is 71531377. The reversal of 71531321 is 12313517.

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

It is a cyclic number.

It is not a de Polignac number, because 71531321 - 2¹⁰ = 71530297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71531221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6311 + ... + 13523.

It is an arithmetic number, because the mean of its divisors is an integer number (9176208).

Almost surely, 2^71531321 is an apocalyptic number.

It is an amenable number.

71531321 is a deficient number, since it is larger than the sum of its proper divisors (1878343).

71531321 is a wasteful number, since it uses less digits than its factorization.

71531321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7471.

The product of its digits is 630, while the sum is 23.

The square root of 71531321 is about 8457.6191094184. The cubic root of 71531321 is about 415.1121214447.

Adding to 71531321 its reverse (12313517), we get a palindrome (83844838).

The spelling of 71531321 in words is "seventy-one million, five hundred thirty-one thousand, three hundred twenty-one".