81025165 has 32 divisors (see below), whose sum is σ = 109670400. Its totient is φ = 57058560.

The previous prime is 81025163. The next prime is 81025169. The reversal of 81025165 is 56152018.

It is not a de Polignac number, because 81025165 - 2¹ = 81025163 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81025163) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 158931 + ... + 159439.

It is an arithmetic number, because the mean of its divisors is an integer number (3427200).

Almost surely, 2^81025165 is an apocalyptic number.

It is an amenable number.

81025165 is a deficient number, since it is larger than the sum of its proper divisors (28645235).

81025165 is a wasteful number, since it uses less digits than its factorization.

81025165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 637.

The product of its (nonzero) digits is 2400, while the sum is 28.

The square root of 81025165 is about 9001.3979469858. The cubic root of 81025165 is about 432.7196741200.

The spelling of 81025165 in words is "eighty-one million, twenty-five thousand, one hundred sixty-five".