71721012 has 24 divisors (see below), whose sum is σ = 182562912. Its totient is φ = 21733600.

The previous prime is 71720959. The next prime is 71721071. The reversal of 71721012 is 21012717.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 71721012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 271539 + ... + 271802.

It is an arithmetic number, because the mean of its divisors is an integer number (7606788).

Almost surely, 2^71721012 is an apocalyptic number.

It is an amenable number.

71721012 is an abundant number, since it is smaller than the sum of its proper divisors (110841900).

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

71721012 is a wasteful number, since it uses less digits than its factorization.

71721012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 543359 (or 543357 counting only the distinct ones).

The product of its (nonzero) digits is 196, while the sum is 21.

The square root of 71721012 is about 8468.8258926489. The cubic root of 71721012 is about 415.4787372131.

Adding to 71721012 its reverse (21012717), we get a palindrome (92733729).

The spelling of 71721012 in words is "seventy-one million, seven hundred twenty-one thousand, twelve".