71988331 has 4 divisors (see below), whose sum is σ = 72353952. Its totient is φ = 71622712.

The previous prime is 71988313. The next prime is 71988337. The reversal of 71988331 is 13388917.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 71988331 - 2⁹ = 71987819 is a prime.

It is a super-2 number, since 2×71988331² = 10364639600331122, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71988337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 182515 + ... + 182908.

It is an arithmetic number, because the mean of its divisors is an integer number (18088488).

Almost surely, 2^71988331 is an apocalyptic number.

71988331 is a deficient number, since it is larger than the sum of its proper divisors (365621).

71988331 is a wasteful number, since it uses less digits than its factorization.

71988331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 365620.

The product of its digits is 36288, while the sum is 40.

The square root of 71988331 is about 8484.5937439573. The cubic root of 71988331 is about 415.9942888608.

The spelling of 71988331 in words is "seventy-one million, nine hundred eighty-eight thousand, three hundred thirty-one".