820661063 has 16 divisors (see below), whose sum is σ = 859209120. Its totient is φ = 783129984.

The previous prime is 820661029. The next prime is 820661081. The reversal of 820661063 is 360166028.

820661063 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 820661063 - 2⁸ = 820660807 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820661263) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 667133 + ... + 668361.

It is an arithmetic number, because the mean of its divisors is an integer number (53700570).

Almost surely, 2^820661063 is an apocalyptic number.

820661063 is a deficient number, since it is larger than the sum of its proper divisors (38548057).

820661063 is a wasteful number, since it uses less digits than its factorization.

820661063 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1618.

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 820661063 is about 28647.1824618059. The cubic root of 820661063 is about 936.2416185198.

The spelling of 820661063 in words is "eight hundred twenty million, six hundred sixty-one thousand, sixty-three".