81602705 has 8 divisors (see below), whose sum is σ = 98933352. Its totient is φ = 64608768.

The previous prime is 81602693. The next prime is 81602711. The reversal of 81602705 is 50720618.

It can be written as a sum of positive squares in 4 ways, for example, as 2446096 + 79156609 = 1564^2 + 8897^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 81602705 - 2¹² = 81598609 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83642 + ... + 84611.

It is an arithmetic number, because the mean of its divisors is an integer number (12366669).

Almost surely, 2^81602705 is an apocalyptic number.

It is an amenable number.

81602705 is a deficient number, since it is larger than the sum of its proper divisors (17330647).

81602705 is a wasteful number, since it uses less digits than its factorization.

81602705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168355.

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 81602705 is about 9033.4215555348. The cubic root of 81602705 is about 433.7453697596.

The spelling of 81602705 in words is "eighty-one million, six hundred two thousand, seven hundred five".