821196305 has 16 divisors (see below), whose sum is σ = 1045774800. Its totient is φ = 616906752.

The previous prime is 821196289. The next prime is 821196319. The reversal of 821196305 is 503691128.

It can be written as a sum of positive squares in 8 ways, for example, as 2835856 + 818360449 = 1684^2 + 28607^2 .

It is a cyclic number.

It is not a de Polignac number, because 821196305 - 2⁴ = 821196289 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27407 + ... + 48923.

It is an arithmetic number, because the mean of its divisors is an integer number (65360925).

Almost surely, 2^821196305 is an apocalyptic number.

821196305 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

821196305 is a deficient number, since it is larger than the sum of its proper divisors (224578495).

821196305 is a wasteful number, since it uses less digits than its factorization.

821196305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21988.

The product of its (nonzero) digits is 12960, while the sum is 35.

The square root of 821196305 is about 28656.5229049164. The cubic root of 821196305 is about 936.4451158199.

The spelling of 821196305 in words is "eight hundred twenty-one million, one hundred ninety-six thousand, three hundred five".