820743202406400 has 3840 divisors, whose sum is σ = 3541626654720000. Its totient is φ = 166471925760000.

The previous prime is 820743202406341. The next prime is 820743202406503. The reversal of 820743202406400 is 4604202347028.

It is a tau number, because it is divible by the number of its divisors (3840).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 5435385446325 + ... + 5435385446475.

It is an arithmetic number, because the mean of its divisors is an integer number (922298608000).

Almost surely, 2^{820743202406400} is an apocalyptic number.

820743202406400 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 820743202406400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1770813327360000).

820743202406400 is an abundant number, since it is smaller than the sum of its proper divisors (2720883452313600).

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

820743202406400 is an equidigital number, since it uses as much as digits as its factorization.

820743202406400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 267 (or 212 counting only the distinct ones).

The product of its (nonzero) digits is 516096, while the sum is 42.

The spelling of 820743202406400 in words is "eight hundred twenty trillion, seven hundred forty-three billion, two hundred two million, four hundred six thousand, four hundred".