71665212 has 24 divisors (see below), whose sum is σ = 171298512. Its totient is φ = 23305600.

The previous prime is 71665201. The next prime is 71665213. The reversal of 71665212 is 21256617.

It is a super-2 number, since 2×71665212² = 10271805222009888, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 71665212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71665213) 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 7 ways as a sum of consecutive naturals, for example, 72339 + ... + 73322.

It is an arithmetic number, because the mean of its divisors is an integer number (7137438).

Almost surely, 2^71665212 is an apocalyptic number.

It is an amenable number.

71665212 is an abundant number, since it is smaller than the sum of its proper divisors (99633300).

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

71665212 is a wasteful number, since it uses less digits than its factorization.

71665212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145709 (or 145707 counting only the distinct ones).

The product of its digits is 5040, while the sum is 30.

The square root of 71665212 is about 8465.5308161981. The cubic root of 71665212 is about 415.3709597389.

The spelling of 71665212 in words is "seventy-one million, six hundred sixty-five thousand, two hundred twelve".