821677409280 has 2816 divisors, whose sum is σ = 3873644544000. Its totient is φ = 163870801920.

The previous prime is 821677409257. The next prime is 821677409299. The reversal of 821677409280 is 82904776128.

It is a happy number.

821677409280 is a `hidden beast` number, since 82 + 16 + 77 + 409 + 2 + 80 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 19108776939 + ... + 19108776981.

It is an arithmetic number, because the mean of its divisors is an integer number (1375584000).

Almost surely, 2^821677409280 is an apocalyptic number.

821677409280 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 821677409280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1936822272000).

821677409280 is an abundant number, since it is smaller than the sum of its proper divisors (3051967134720).

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

821677409280 is a wasteful number, since it uses less digits than its factorization.

821677409280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142 (or 104 counting only the distinct ones).

The product of its (nonzero) digits is 2709504, while the sum is 54.

The spelling of 821677409280 in words is "eight hundred twenty-one billion, six hundred seventy-seven million, four hundred nine thousand, two hundred eighty".