71999997 has 4 divisors (see below), whose sum is σ = 96000000. Its totient is φ = 47999996.

The previous prime is 71999989. The next prime is 71999999. The reversal of 71999997 is 79999917.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 71999997 - 2³ = 71999989 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 71999997.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71999999) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11999997 + ... + 12000002.

It is an arithmetic number, because the mean of its divisors is an integer number (24000000).

Almost surely, 2^71999997 is an apocalyptic number.

It is an amenable number.

71999997 is a deficient number, since it is larger than the sum of its proper divisors (24000003).

71999997 is a wasteful number, since it uses less digits than its factorization.

71999997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24000002.

The product of its digits is 2893401, while the sum is 60.

The square root of 71999997 is about 8485.2811974619. The cubic root of 71999997 is about 416.0167588324.

The spelling of 71999997 in words is "seventy-one million, nine hundred ninety-nine thousand, nine hundred ninety-seven".