71724221 has 8 divisors (see below), whose sum is σ = 78103200. Its totient is φ = 65605680.

The previous prime is 71724197. The next prime is 71724223. The reversal of 71724221 is 12242717.

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 71724221 - 2¹⁴ = 71707837 is a prime.

It is a super-3 number, since 3×71724221³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71724223) 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, 64535 + ... + 65636.

It is an arithmetic number, because the mean of its divisors is an integer number (9762900).

Almost surely, 2^71724221 is an apocalyptic number.

It is an amenable number.

71724221 is a deficient number, since it is larger than the sum of its proper divisors (6378979).

71724221 is a wasteful number, since it uses less digits than its factorization.

71724221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130219.

The product of its digits is 1568, while the sum is 26.

The square root of 71724221 is about 8469.0153500865. The cubic root of 71724221 is about 415.4849336835.

Adding to 71724221 its reverse (12242717), we get a palindrome (83966938).

The spelling of 71724221 in words is "seventy-one million, seven hundred twenty-four thousand, two hundred twenty-one".