820755431424 has 432 divisors, whose sum is σ = 2499623682192. Its totient is φ = 269072990208.

The previous prime is 820755431423. The next prime is 820755431479. The reversal of 820755431424 is 424134557028.

820755431424 is a `hidden beast` number, since 8 + 2 + 0 + 75 + 543 + 14 + 24 = 666.

It is a tau number, because it is divible by the number of its divisors (432).

It is a self number, because there is not a number n which added to its sum of digits gives 820755431424.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820755431423) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2325086032 + ... + 2325086384.

It is an arithmetic number, because the mean of its divisors is an integer number (5786165931).

Almost surely, 2^820755431424 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 820755431424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1249811841096).

820755431424 is an abundant number, since it is smaller than the sum of its proper divisors (1678868250768).

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

820755431424 is an frugal number, since it uses more digits than its factorization.

820755431424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 475 (or 431 counting only the distinct ones).

The product of its (nonzero) digits is 1075200, while the sum is 45.

The spelling of 820755431424 in words is "eight hundred twenty billion, seven hundred fifty-five million, four hundred thirty-one thousand, four hundred twenty-four".