820541865 has 64 divisors (see below), whose sum is σ = 1549078272. Its totient is φ = 365644800.

The previous prime is 820541833. The next prime is 820541879. The reversal of 820541865 is 568145028.

820541865 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 820541865 - 2⁵ = 820541833 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 593475 + ... + 594855.

It is an arithmetic number, because the mean of its divisors is an integer number (24204348).

Almost surely, 2^820541865 is an apocalyptic number.

It is an amenable number.

820541865 is a deficient number, since it is larger than the sum of its proper divisors (728536407).

820541865 is a wasteful number, since it uses less digits than its factorization.

820541865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1690.

The product of its (nonzero) digits is 76800, while the sum is 39.

The square root of 820541865 is about 28645.1019373295. The cubic root of 820541865 is about 936.1962877749.

The spelling of 820541865 in words is "eight hundred twenty million, five hundred forty-one thousand, eight hundred sixty-five".