71997 has 8 divisors (see below), whose sum is σ = 97344. Its totient is φ = 47328.

The previous prime is 71993. The next prime is 71999. The reversal of 71997 is 79917.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 71997 - 2² = 71993 is a prime.

It is an Ulam number.

71997 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71993) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 193 + ... + 425.

It is an arithmetic number, because the mean of its divisors is an integer number (12168).

2⁷¹⁹⁹⁷ is an apocalyptic number.

It is an amenable number.

71997 is a deficient number, since it is larger than the sum of its proper divisors (25347).

71997 is a wasteful number, since it uses less digits than its factorization.

71997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 339.

The product of its digits is 3969, while the sum is 33.

The square root of 71997 is about 268.3225670718. The cubic root of 71997 is about 41.6010986520.

The spelling of 71997 in words is "seventy-one thousand, nine hundred ninety-seven".