821773403136 has 1408 divisors, whose sum is σ = 3093884928000. Its totient is φ = 212840939520.

The previous prime is 821773403123. The next prime is 821773403159. The reversal of 821773403136 is 631304377128.

821773403136 is a `hidden beast` number, since 8 + 2 + 177 + 340 + 3 + 136 = 666.

It is a super-2 number, since 2×821773403136² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 821773403091 and 821773403100.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 9233408980 + ... + 9233409068.

Almost surely, 2^821773403136 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 821773403136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1546942464000).

821773403136 is an abundant number, since it is smaller than the sum of its proper divisors (2272111524864).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

821773403136 is an equidigital number, since it uses as much as digits as its factorization.

821773403136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187 (or 151 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 45.

The spelling of 821773403136 in words is "eight hundred twenty-one billion, seven hundred seventy-three million, four hundred three thousand, one hundred thirty-six".