71991000280 has 64 divisors (see below), whose sum is σ = 165620518560. Its totient is φ = 28153003008.

The previous prime is 71991000269. The next prime is 71991000299. The reversal of 71991000280 is 8200019917.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 539964 + ... + 659956.

Almost surely, 2^71991000280 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 71991000280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82810259280).

71991000280 is an abundant number, since it is smaller than the sum of its proper divisors (93629518280).

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

71991000280 is a wasteful number, since it uses less digits than its factorization.

71991000280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120340 (or 120336 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 37.

The spelling of 71991000280 in words is "seventy-one billion, nine hundred ninety-one million, two hundred eighty", and thus it is an aban number.