71326561 has 4 divisors (see below), whose sum is σ = 71470000. Its totient is φ = 71183124.

The previous prime is 71326553. The next prime is 71326571. The reversal of 71326561 is 16562317.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 71326561 - 2³ = 71326553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71326501) 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, 70971 + ... + 71968.

It is an arithmetic number, because the mean of its divisors is an integer number (17867500).

Almost surely, 2^71326561 is an apocalyptic number.

It is an amenable number.

71326561 is a deficient number, since it is larger than the sum of its proper divisors (143439).

71326561 is a wasteful number, since it uses less digits than its factorization.

71326561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143438.

The product of its digits is 7560, while the sum is 31.

The square root of 71326561 is about 8445.5053726820. The cubic root of 71326561 is about 414.7156536724.

Adding to 71326561 its reverse (16562317), we get a palindrome (87888878).

The spelling of 71326561 in words is "seventy-one million, three hundred twenty-six thousand, five hundred sixty-one".