71998913 has 4 divisors (see below), whose sum is σ = 82284480. Its totient is φ = 61713348.

The previous prime is 71998907. The next prime is 71998921. The reversal of 71998913 is 31989917.

It is a happy number.

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 71998913 - 2¹⁶ = 71933377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71998903) 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, 5142773 + ... + 5142786.

It is an arithmetic number, because the mean of its divisors is an integer number (20571120).

Almost surely, 2^71998913 is an apocalyptic number.

It is an amenable number.

71998913 is a deficient number, since it is larger than the sum of its proper divisors (10285567).

71998913 is a wasteful number, since it uses less digits than its factorization.

71998913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10285566.

The product of its digits is 122472, while the sum is 47.

The square root of 71998913 is about 8485.2173219076. The cubic root of 71998913 is about 416.0146710340.

The spelling of 71998913 in words is "seventy-one million, nine hundred ninety-eight thousand, nine hundred thirteen".