857821464560 has 80 divisors (see below), whose sum is σ = 2029282072992. Its totient is φ = 337145318400.

The previous prime is 857821464517. The next prime is 857821464569. The reversal of 857821464560 is 65464128758.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 857821464496 and 857821464505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (857821464569) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4528550 + ... + 4714170.

Almost surely, 2^857821464560 is an apocalyptic number.

857821464560 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 857821464560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1014641036496).

857821464560 is an abundant number, since it is smaller than the sum of its proper divisors (1171460608432).

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

857821464560 is a wasteful number, since it uses less digits than its factorization.

857821464560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186642 (or 186636 counting only the distinct ones).

The product of its (nonzero) digits is 12902400, while the sum is 56.

The spelling of 857821464560 in words is "eight hundred fifty-seven billion, eight hundred twenty-one million, four hundred sixty-four thousand, five hundred sixty".