820667801 has 4 divisors (see below), whose sum is σ = 820726452. Its totient is φ = 820609152.

The previous prime is 820667789. The next prime is 820667833. The reversal of 820667801 is 108766028.

820667801 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, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 419266576 + 401401225 = 20476^2 + 20035^2 .

It is a cyclic number.

It is not a de Polignac number, because 820667801 - 2¹⁸ = 820405657 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (820663801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5261 + ... + 40853.

It is an arithmetic number, because the mean of its divisors is an integer number (205181613).

Almost surely, 2^820667801 is an apocalyptic number.

It is an amenable number.

820667801 is a deficient number, since it is larger than the sum of its proper divisors (58651).

820667801 is a wasteful number, since it uses less digits than its factorization.

820667801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58650.

The product of its (nonzero) digits is 32256, while the sum is 38.

The square root of 820667801 is about 28647.3000647530. The cubic root of 820667801 is about 936.2441808358.

The spelling of 820667801 in words is "eight hundred twenty million, six hundred sixty-seven thousand, eight hundred one".