71681687 has 8 divisors (see below), whose sum is σ = 89369472. Its totient is φ = 55855800.

The previous prime is 71681683. The next prime is 71681689. The reversal of 71681687 is 78618617.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 71681687 - 2² = 71681683 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71681681) 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 7 ways as a sum of consecutive naturals, for example, 465389 + ... + 465542.

It is an arithmetic number, because the mean of its divisors is an integer number (11171184).

Almost surely, 2^71681687 is an apocalyptic number.

71681687 is a gapful number since it is divisible by the number (77) formed by its first and last digit.

71681687 is a deficient number, since it is larger than the sum of its proper divisors (17687785).

71681687 is a wasteful number, since it uses less digits than its factorization.

71681687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 930949.

The product of its digits is 112896, while the sum is 44.

The square root of 71681687 is about 8466.5038238933. The cubic root of 71681687 is about 415.4027869535.

The spelling of 71681687 in words is "seventy-one million, six hundred eighty-one thousand, six hundred eighty-seven".