820465 has 4 divisors (see below), whose sum is σ = 984564. Its totient is φ = 656368.

The previous prime is 820459. The next prime is 820481. The reversal of 820465 is 564028.

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 345744 + 474721 = 588^2 + 689^2 .

It is a cyclic number.

It is not a de Polignac number, because 820465 - 2¹⁵ = 787697 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82042 + ... + 82051.

It is an arithmetic number, because the mean of its divisors is an integer number (246141).

2⁸²⁰⁴⁶⁵ is an apocalyptic number.

It is an amenable number.

820465 is a deficient number, since it is larger than the sum of its proper divisors (164099).

820465 is a wasteful number, since it uses less digits than its factorization.

820465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164098.

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 820465 is about 905.7952307227. The cubic root of 820465 is about 93.6167053851.

The spelling of 820465 in words is "eight hundred twenty thousand, four hundred sixty-five".