81365170 has 16 divisors (see below), whose sum is σ = 146622168. Its totient is φ = 32509440.

The previous prime is 81365161. The next prime is 81365171. The reversal of 81365170 is 7156318.

It can be written as a sum of positive squares in 4 ways, for example, as 72914521 + 8450649 = 8539^2 + 2907^2 .

It is not an unprimeable number, because it can be changed into a prime (81365171) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5890 + ... + 14050.

Almost surely, 2^81365170 is an apocalyptic number.

81365170 is a deficient number, since it is larger than the sum of its proper divisors (65256998).

81365170 is a wasteful number, since it uses less digits than its factorization.

81365170 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9165.

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 81365170 is about 9020.2644085415. The cubic root of 81365170 is about 433.3241017100.

The spelling of 81365170 in words is "eighty-one million, three hundred sixty-five thousand, one hundred seventy".