71554221 has 6 divisors (see below), whose sum is σ = 103356110. Its totient is φ = 47702808.

The previous prime is 71554211. The next prime is 71554237. The reversal of 71554221 is 12245517.

It can be written as a sum of positive squares in only one way, i.e., 71318025 + 236196 = 8445^2 + 486^2 .

It is a de Polignac number, because none of the positive numbers 2^k-71554221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71554201) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 3975226 + ... + 3975243.

Almost surely, 2^71554221 is an apocalyptic number.

It is an amenable number.

71554221 is a deficient number, since it is larger than the sum of its proper divisors (31801889).

71554221 is a wasteful number, since it uses less digits than its factorization.

71554221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7950475 (or 7950472 counting only the distinct ones).

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

The square root of 71554221 is about 8458.9728099811. The cubic root of 71554221 is about 415.1564146447.

Adding to 71554221 its reverse (12245517), we get a palindrome (83799738).

The spelling of 71554221 in words is "seventy-one million, five hundred fifty-four thousand, two hundred twenty-one".