71321631 has 4 divisors (see below), whose sum is σ = 95095512. Its totient is φ = 47547752.

The previous prime is 71321617. The next prime is 71321693. The reversal of 71321631 is 13612317.

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

It is a cyclic number.

It is not a de Polignac number, because 71321631 - 2¹⁹ = 70797343 is a prime.

It is a super-2 number, since 2×71321631² = 10173550097000322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71321431) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11886936 + ... + 11886941.

It is an arithmetic number, because the mean of its divisors is an integer number (23773878).

Almost surely, 2^71321631 is an apocalyptic number.

71321631 is a deficient number, since it is larger than the sum of its proper divisors (23773881).

71321631 is a wasteful number, since it uses less digits than its factorization.

71321631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23773880.

The product of its digits is 756, while the sum is 24.

The square root of 71321631 is about 8445.2134964132. The cubic root of 71321631 is about 414.7060985817.

Adding to 71321631 its reverse (13612317), we get a palindrome (84933948).

The spelling of 71321631 in words is "seventy-one million, three hundred twenty-one thousand, six hundred thirty-one".