71439681 has 4 divisors (see below), whose sum is σ = 95252912. Its totient is φ = 47626452.

The previous prime is 71439653. The next prime is 71439701. The reversal of 71439681 is 18693417.

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 not a de Polignac number, because 71439681 - 2⁵ = 71439649 is a prime.

It is a super-2 number, since 2×71439681² = 10207256042763522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71439281) 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, 11906611 + ... + 11906616.

It is an arithmetic number, because the mean of its divisors is an integer number (23813228).

Almost surely, 2^71439681 is an apocalyptic number.

It is an amenable number.

71439681 is a deficient number, since it is larger than the sum of its proper divisors (23813231).

71439681 is a wasteful number, since it uses less digits than its factorization.

71439681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23813230.

The product of its digits is 36288, while the sum is 39.

The square root of 71439681 is about 8452.1997728402. The cubic root of 71439681 is about 414.9347766080.

The spelling of 71439681 in words is "seventy-one million, four hundred thirty-nine thousand, six hundred eighty-one".