820677647 has 2 divisors, whose sum is σ = 820677648. Its totient is φ = 820677646.

The previous prime is 820677631. The next prime is 820677653. The reversal of 820677647 is 746776028.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 820677647 - 2⁴ = 820677631 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (820677047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410338823 + 410338824.

It is an arithmetic number, because the mean of its divisors is an integer number (410338824).

Almost surely, 2^820677647 is an apocalyptic number.

820677647 is a deficient number, since it is larger than the sum of its proper divisors (1).

820677647 is an equidigital number, since it uses as much as digits as its factorization.

820677647 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 790272, while the sum is 47.

The square root of 820677647 is about 28647.4719128931. The cubic root of 820677647 is about 936.2479250318.

The spelling of 820677647 in words is "eight hundred twenty million, six hundred seventy-seven thousand, six hundred forty-seven".