821696366 has 16 divisors (see below), whose sum is σ = 1241947728. Its totient is φ = 407721600.

The previous prime is 821696357. The next prime is 821696387. The reversal of 821696366 is 663696128.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 821696366.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 285776 + ... + 288636.

It is an arithmetic number, because the mean of its divisors is an integer number (77621733).

Almost surely, 2^821696366 is an apocalyptic number.

821696366 is a deficient number, since it is larger than the sum of its proper divisors (420251362).

821696366 is a wasteful number, since it uses less digits than its factorization.

821696366 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3907.

The product of its digits is 559872, while the sum is 47.

The square root of 821696366 is about 28665.2466586283. The cubic root of 821696366 is about 936.6351575345.

The spelling of 821696366 in words is "eight hundred twenty-one million, six hundred ninety-six thousand, three hundred sixty-six".