71997128 has 64 divisors (see below), whose sum is σ = 161894400. Its totient is φ = 29367360.

The previous prime is 71997127. The next prime is 71997131. The reversal of 71997128 is 82179917.

It is not an unprimeable number, because it can be changed into a prime (71997127) 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 15 ways as a sum of consecutive naturals, for example, 116003 + ... + 116621.

It is an arithmetic number, because the mean of its divisors is an integer number (2529600).

Almost surely, 2^71997128 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 71997128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80947200).

71997128 is an abundant number, since it is smaller than the sum of its proper divisors (89897272).

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

71997128 is a wasteful number, since it uses less digits than its factorization.

71997128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 730 (or 726 counting only the distinct ones).

The product of its digits is 63504, while the sum is 44.

The square root of 71997128 is about 8485.1121383279. The cubic root of 71997128 is about 416.0112330547.

The spelling of 71997128 in words is "seventy-one million, nine hundred ninety-seven thousand, one hundred twenty-eight".