71109681 has 4 divisors (see below), whose sum is σ = 94812912. Its totient is φ = 47406452.

The previous prime is 71109679. The next prime is 71109683. The reversal of 71109681 is 18690117.

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 an interprime number because it is at equal distance from previous prime (71109679) and next prime (71109683).

It is a cyclic number.

It is not a de Polignac number, because 71109681 - 2¹ = 71109679 is a prime.

It is a super-2 number, since 2×71109681² = 10113173463843522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (71109683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11851611 + ... + 11851616.

It is an arithmetic number, because the mean of its divisors is an integer number (23703228).

Almost surely, 2^71109681 is an apocalyptic number.

It is an amenable number.

71109681 is a deficient number, since it is larger than the sum of its proper divisors (23703231).

71109681 is a wasteful number, since it uses less digits than its factorization.

71109681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23703230.

The product of its (nonzero) digits is 3024, while the sum is 33.

The square root of 71109681 is about 8432.6556315315. The cubic root of 71109681 is about 414.2948901371.

Adding to 71109681 its reverse (18690117), we get a palindrome (89799798).

The spelling of 71109681 in words is "seventy-one million, one hundred nine thousand, six hundred eighty-one".