71217220 has 48 divisors (see below), whose sum is σ = 153861120. Its totient is φ = 27676544.

The previous prime is 71217197. The next prime is 71217227. The reversal of 71217220 is 2271217.

It is a junction number, because it is equal to n+sod(n) for n = 71217191 and 71217200.

It is not an unprimeable number, because it can be changed into a prime (71217227) 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, 224502 + ... + 224818.

It is an arithmetic number, because the mean of its divisors is an integer number (3205440).

Almost surely, 2^71217220 is an apocalyptic number.

It is an amenable number.

71217220 is an abundant number, since it is smaller than the sum of its proper divisors (82643900).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

71217220 is a wasteful number, since it uses less digits than its factorization.

71217220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 612 (or 610 counting only the distinct ones).

The product of its (nonzero) digits is 392, while the sum is 22.

The square root of 71217220 is about 8439.0295650626. The cubic root of 71217220 is about 414.5036306693.

Adding to 71217220 its reverse (2271217), we get a palindrome (73488437).

It can be divided in two parts, 7121 and 7220, that added together give a palindrome (14341).

The spelling of 71217220 in words is "seventy-one million, two hundred seventeen thousand, two hundred twenty".