820540423 has 2 divisors, whose sum is σ = 820540424. Its totient is φ = 820540422.

The previous prime is 820540361. The next prime is 820540499. The reversal of 820540423 is 324045028.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 820540423 - 2¹³ = 820532231 is a prime.

It is equal to p_42147820 and since 820540423 and 42147820 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 820540391 and 820540400.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (820546423) 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, 410270211 + 410270212.

It is an arithmetic number, because the mean of its divisors is an integer number (410270212).

Almost surely, 2^820540423 is an apocalyptic number.

820540423 is a deficient number, since it is larger than the sum of its proper divisors (1).

820540423 is an equidigital number, since it uses as much as digits as its factorization.

820540423 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7680, while the sum is 28.

The square root of 820540423 is about 28645.0767672213. The cubic root of 820540423 is about 936.1957393585.

The spelling of 820540423 in words is "eight hundred twenty million, five hundred forty thousand, four hundred twenty-three".