71491990068 has 72 divisors (see below), whose sum is σ = 191370036480. Its totient is φ = 23056941600.

The previous prime is 71491990007. The next prime is 71491990117. The reversal of 71491990068 is 86009919417.

71491990068 is a `hidden beast` number, since 7 + 1 + 491 + 9 + 90 + 0 + 68 = 666.

It is a super-2 number, since 2×71491990068² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 71491989996 and 71491990023.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 15468798 + ... + 15473418.

Almost surely, 2^71491990068 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 71491990068, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95685018240).

71491990068 is an abundant number, since it is smaller than the sum of its proper divisors (119878046412).

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

71491990068 is an equidigital number, since it uses as much as digits as its factorization.

71491990068 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9286 (or 4657 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 54.

The spelling of 71491990068 in words is "seventy-one billion, four hundred ninety-one million, nine hundred ninety thousand, sixty-eight".