820019564647 has 2 divisors, whose sum is σ = 820019564648. Its totient is φ = 820019564646.

The previous prime is 820019564641. The next prime is 820019564657. The reversal of 820019564647 is 746465910028.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 820019564647 - 2³⁵ = 785659826279 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 820019564594 and 820019564603.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (820019564641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410009782323 + 410009782324.

It is an arithmetic number, because the mean of its divisors is an integer number (410009782324).

Almost surely, 2^820019564647 is an apocalyptic number.

820019564647 is a deficient number, since it is larger than the sum of its proper divisors (1).

820019564647 is an equidigital number, since it uses as much as digits as its factorization.

820019564647 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2903040, while the sum is 52.

The spelling of 820019564647 in words is "eight hundred twenty billion, nineteen million, five hundred sixty-four thousand, six hundred forty-seven".