71664144820 has 12 divisors (see below), whose sum is σ = 150494704164. Its totient is φ = 28665657920.

The previous prime is 71664144787. The next prime is 71664144859. The reversal of 71664144820 is 2844146617.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 28024099216 + 43640045604 = 167404^2 + 208902^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1791603601 + ... + 1791603640.

It is an arithmetic number, because the mean of its divisors is an integer number (12541225347).

Almost surely, 2^71664144820 is an apocalyptic number.

It is an amenable number.

71664144820 is an abundant number, since it is smaller than the sum of its proper divisors (78830559344).

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

71664144820 is a wasteful number, since it uses less digits than its factorization.

71664144820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3583207250 (or 3583207248 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 43.

The spelling of 71664144820 in words is "seventy-one billion, six hundred sixty-four million, one hundred forty-four thousand, eight hundred twenty".