71681821393920 has 176 divisors, whose sum is σ = 235466309254848. Its totient is φ = 18598526484480.

The previous prime is 71681821393907. The next prime is 71681821393921. The reversal of 71681821393920 is 2939312818617.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is not an unprimeable number, because it can be changed into a prime (71681821393921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62496346 + ... + 63632985.

Almost surely, 2^{71681821393920} is an apocalyptic number.

It is an amenable number.

71681821393920 is an abundant number, since it is smaller than the sum of its proper divisors (163784487860928).

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

71681821393920 is a wasteful number, since it uses less digits than its factorization.

71681821393920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126129396 (or 126129378 counting only the distinct ones).

The product of its (nonzero) digits is 7838208, while the sum is 60.

The spelling of 71681821393920 in words is "seventy-one trillion, six hundred eighty-one billion, eight hundred twenty-one million, three hundred ninety-three thousand, nine hundred twenty".