81162845 has 8 divisors (see below), whose sum is σ = 103124664. Its totient is φ = 61110784.

The previous prime is 81162839. The next prime is 81162847. The reversal of 81162845 is 54826118.

It can be written as a sum of positive squares in 4 ways, for example, as 16826404 + 64336441 = 4102^2 + 8021^2 .

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

It is not a de Polignac number, because 81162845 - 2¹⁶ = 81097309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81162847) 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, 477344 + ... + 477513.

It is an arithmetic number, because the mean of its divisors is an integer number (12890583).

Almost surely, 2^81162845 is an apocalyptic number.

81162845 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

81162845 is a deficient number, since it is larger than the sum of its proper divisors (21961819).

81162845 is a wasteful number, since it uses less digits than its factorization.

81162845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 954879.

The product of its digits is 15360, while the sum is 35.

The square root of 81162845 is about 9009.0424019426. The cubic root of 81162845 is about 432.9646314808.

The spelling of 81162845 in words is "eighty-one million, one hundred sixty-two thousand, eight hundred forty-five".