81709514 has 24 divisors (see below), whose sum is σ = 131681700. Its totient is φ = 37892736.

The previous prime is 81709499. The next prime is 81709549. The reversal of 81709514 is 41590718.

It can be written as a sum of positive squares in 2 ways, for example, as 81306289 + 403225 = 9017^2 + 635^2 .

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 548312 + ... + 548460.

Almost surely, 2^81709514 is an apocalyptic number.

81709514 is a deficient number, since it is larger than the sum of its proper divisors (49972186).

81709514 is a wasteful number, since it uses less digits than its factorization.

81709514 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 422 (or 295 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 35.

The square root of 81709514 is about 9039.3315018313. The cubic root of 81709514 is about 433.9345289758.

The spelling of 81709514 in words is "eighty-one million, seven hundred nine thousand, five hundred fourteen".