820181465 has 4 divisors (see below), whose sum is σ = 984217764. Its totient is φ = 656145168.

The previous prime is 820181431. The next prime is 820181489. The reversal of 820181465 is 564181028.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 136515856 + 683665609 = 11684^2 + 26147^2 .

It is a cyclic number.

It is not a de Polignac number, because 820181465 - 2⁸ = 820181209 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82018142 + ... + 82018151.

It is an arithmetic number, because the mean of its divisors is an integer number (246054441).

Almost surely, 2^820181465 is an apocalyptic number.

It is an amenable number.

820181465 is a deficient number, since it is larger than the sum of its proper divisors (164036299).

820181465 is a wasteful number, since it uses less digits than its factorization.

820181465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164036298.

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

The square root of 820181465 is about 28638.8104676154. The cubic root of 820181465 is about 936.0592017154.

The spelling of 820181465 in words is "eight hundred twenty million, one hundred eighty-one thousand, four hundred sixty-five".