71545221 has 16 divisors (see below), whose sum is σ = 115629120. Its totient is φ = 43360560.

The previous prime is 71545219. The next prime is 71545223. The reversal of 71545221 is 12254517.

It is an interprime number because it is at equal distance from previous prime (71545219) and next prime (71545223).

It is not a de Polignac number, because 71545221 - 2¹ = 71545219 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71545223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 120150 + ... + 120743.

It is an arithmetic number, because the mean of its divisors is an integer number (7226820).

Almost surely, 2^71545221 is an apocalyptic number.

It is an amenable number.

71545221 is a deficient number, since it is larger than the sum of its proper divisors (44083899).

71545221 is a wasteful number, since it uses less digits than its factorization.

71545221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240913 (or 240907 counting only the distinct ones).

The product of its digits is 2800, while the sum is 27.

The square root of 71545221 is about 8458.4408137670. The cubic root of 71545221 is about 415.1390079642.

Adding to 71545221 its reverse (12254517), we get a palindrome (83799738).

The spelling of 71545221 in words is "seventy-one million, five hundred forty-five thousand, two hundred twenty-one".