81689713 has 24 divisors (see below), whose sum is σ = 98496000. Its totient is φ = 67511808.

The previous prime is 81689711. The next prime is 81689717. The reversal of 81689713 is 31798618.

It is not a de Polignac number, because 81689713 - 2¹ = 81689711 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81689713.

It is not an unprimeable number, because it can be changed into a prime (81689711) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 181713 + ... + 182161.

It is an arithmetic number, because the mean of its divisors is an integer number (4104000).

Almost surely, 2^81689713 is an apocalyptic number.

It is an amenable number.

81689713 is a deficient number, since it is larger than the sum of its proper divisors (16806287).

81689713 is a wasteful number, since it uses less digits than its factorization.

81689713 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 589 (or 582 counting only the distinct ones).

The product of its digits is 72576, while the sum is 43.

The square root of 81689713 is about 9038.2361664210. The cubic root of 81689713 is about 433.8994737689.

The spelling of 81689713 in words is "eighty-one million, six hundred eighty-nine thousand, seven hundred thirteen".