820732440 has 192 divisors, whose sum is σ = 2779764480. Its totient is φ = 192249600.

The previous prime is 820732411. The next prime is 820732463. The reversal of 820732440 is 44237028.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 820732398 and 820732407.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1268197 + ... + 1268843.

It is an arithmetic number, because the mean of its divisors is an integer number (14477940).

Almost surely, 2^820732440 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 820732440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1389882240).

820732440 is an abundant number, since it is smaller than the sum of its proper divisors (1959032040).

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

820732440 is a wasteful number, since it uses less digits than its factorization.

820732440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 734 (or 699 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 30.

The square root of 820732440 is about 28648.4282291368. The cubic root of 820732440 is about 936.2687609394.

Adding to 820732440 its reverse (44237028), we get a palindrome (864969468).

The spelling of 820732440 in words is "eight hundred twenty million, seven hundred thirty-two thousand, four hundred forty".