821773403091 has 12 divisors (see below), whose sum is σ = 1204722535432. Its totient is φ = 539672085216.

The previous prime is 821773402987. The next prime is 821773403123. The reversal of 821773403091 is 190304377128.

821773403091 is a `hidden beast` number, since 8 + 217 + 7 + 340 + 3 + 0 + 91 = 666.

It is not a de Polignac number, because 821773403091 - 2¹⁰ = 821773402067 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (821773403491) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 681403546 + ... + 681404751.

Almost surely, 2^821773403091 is an apocalyptic number.

821773403091 is a deficient number, since it is larger than the sum of its proper divisors (382949132341).

821773403091 is a wasteful number, since it uses less digits than its factorization.

821773403091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1362808370 (or 1362808367 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 45.

The spelling of 821773403091 in words is "eight hundred twenty-one billion, seven hundred seventy-three million, four hundred three thousand, ninety-one".