81275165 has 8 divisors (see below), whose sum is σ = 97746360. Its totient is φ = 64876032.

The previous prime is 81275101. The next prime is 81275189. The reversal of 81275165 is 56157218.

It can be written as a sum of positive squares in 4 ways, for example, as 45010681 + 36264484 = 6709^2 + 6022^2 .

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 81275165 - 2⁶ = 81275101 is a prime.

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 7 ways as a sum of consecutive naturals, for example, 15500 + ... + 20069.

It is an arithmetic number, because the mean of its divisors is an integer number (12218295).

Almost surely, 2^81275165 is an apocalyptic number.

It is an amenable number.

81275165 is a deficient number, since it is larger than the sum of its proper divisors (16471195).

81275165 is a wasteful number, since it uses less digits than its factorization.

81275165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36031.

The product of its digits is 16800, while the sum is 35.

The square root of 81275165 is about 9015.2739836347. The cubic root of 81275165 is about 433.1642637616.

The spelling of 81275165 in words is "eighty-one million, two hundred seventy-five thousand, one hundred sixty-five".