820421699 has 2 divisors, whose sum is σ = 820421700. Its totient is φ = 820421698.

The previous prime is 820421621. The next prime is 820421713. The reversal of 820421699 is 996124028.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 820421699 - 2⁸ = 820421443 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (820421099) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410210849 + 410210850.

It is an arithmetic number, because the mean of its divisors is an integer number (410210850).

Almost surely, 2^820421699 is an apocalyptic number.

820421699 is a deficient number, since it is larger than the sum of its proper divisors (1).

820421699 is an equidigital number, since it uses as much as digits as its factorization.

820421699 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 820421699 is about 28643.0043640677. The cubic root of 820421699 is about 936.1505844577.

The spelling of 820421699 in words is "eight hundred twenty million, four hundred twenty-one thousand, six hundred ninety-nine".