820861640801 has 2 divisors, whose sum is σ = 820861640802. Its totient is φ = 820861640800.

The previous prime is 820861640759. The next prime is 820861640873. The reversal of 820861640801 is 108046168028.

820861640801 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 705532801600 + 115328839201 = 839960^2 + 339601^2 .

It is a cyclic number.

It is not a de Polignac number, because 820861640801 - 2⁶ = 820861640737 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (820861640101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410430820400 + 410430820401.

It is an arithmetic number, because the mean of its divisors is an integer number (410430820401).

Almost surely, 2^820861640801 is an apocalyptic number.

It is an amenable number.

820861640801 is a deficient number, since it is larger than the sum of its proper divisors (1).

820861640801 is an equidigital number, since it uses as much as digits as its factorization.

820861640801 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 147456, while the sum is 44.

The spelling of 820861640801 in words is "eight hundred twenty billion, eight hundred sixty-one million, six hundred forty thousand, eight hundred one".