821918863 has 2 divisors, whose sum is σ = 821918864. Its totient is φ = 821918862.

The previous prime is 821918843. The next prime is 821918879. The reversal of 821918863 is 368819128.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 821918863 - 2⁹ = 821918351 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (821918803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410959431 + 410959432.

It is an arithmetic number, because the mean of its divisors is an integer number (410959432).

Almost surely, 2^821918863 is an apocalyptic number.

821918863 is a deficient number, since it is larger than the sum of its proper divisors (1).

821918863 is an equidigital number, since it uses as much as digits as its factorization.

821918863 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 165888, while the sum is 46.

The square root of 821918863 is about 28669.1273498166. The cubic root of 821918863 is about 936.7196898566.

The spelling of 821918863 in words is "eight hundred twenty-one million, nine hundred eighteen thousand, eight hundred sixty-three".