820765855 has 16 divisors (see below), whose sum is σ = 1212208704. Its totient is φ = 519517440.

The previous prime is 820765849. The next prime is 820765871. The reversal of 820765855 is 558567028.

It is not a de Polignac number, because 820765855 - 2⁵ = 820765823 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 901486 + ... + 902395.

It is an arithmetic number, because the mean of its divisors is an integer number (75763044).

Almost surely, 2^820765855 is an apocalyptic number.

820765855 is a deficient number, since it is larger than the sum of its proper divisors (391442849).

820765855 is a wasteful number, since it uses less digits than its factorization.

820765855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1803906.

The product of its (nonzero) digits is 672000, while the sum is 46.

The square root of 820765855 is about 28649.0114140087. The cubic root of 820765855 is about 936.2814670681.

The spelling of 820765855 in words is "eight hundred twenty million, seven hundred sixty-five thousand, eight hundred fifty-five".