820546880645 has 4 divisors (see below), whose sum is σ = 984656256780. Its totient is φ = 656437504512.

The previous prime is 820546880623. The next prime is 820546880711. The reversal of 820546880645 is 546088645028.

820546880645 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 469673096929 + 350873783716 = 685327^2 + 592346^2 .

It is a cyclic number.

It is not a de Polignac number, because 820546880645 - 2⁶ = 820546880581 is a prime.

It is a congruent 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, 82054688060 + ... + 82054688069.

It is an arithmetic number, because the mean of its divisors is an integer number (246164064195).

Almost surely, 2^820546880645 is an apocalyptic number.

It is an amenable number.

820546880645 is a deficient number, since it is larger than the sum of its proper divisors (164109376135).

820546880645 is a wasteful number, since it uses less digits than its factorization.

820546880645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164109376134.

The product of its (nonzero) digits is 14745600, while the sum is 56.

The spelling of 820546880645 in words is "eight hundred twenty billion, five hundred forty-six million, eight hundred eighty thousand, six hundred forty-five".