821259140 has 48 divisors (see below), whose sum is σ = 1873812528. Its totient is φ = 300539904.

The previous prime is 821259139. The next prime is 821259143. The reversal of 821259140 is 41952128.

821259140 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 49308484 + 771950656 = 7022^2 + 27784^2 .

It is a junction number, because it is equal to n+sod(n) for n = 821259097 and 821259106.

It is not an unprimeable number, because it can be changed into a prime (821259143) 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, 15404 + ... + 43356.

It is an arithmetic number, because the mean of its divisors is an integer number (39037761).

Almost surely, 2^821259140 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 821259140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (936906264).

821259140 is an abundant number, since it is smaller than the sum of its proper divisors (1052553388).

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

821259140 is a wasteful number, since it uses less digits than its factorization.

821259140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28088 (or 28086 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 32.

The square root of 821259140 is about 28657.6192311923. The cubic root of 821259140 is about 936.4689996862.

The spelling of 821259140 in words is "eight hundred twenty-one million, two hundred fifty-nine thousand, one hundred forty".