821145204 has 108 divisors (see below), whose sum is σ = 2300538240. Its totient is φ = 246760800.

The previous prime is 821145191. The next prime is 821145209. The reversal of 821145204 is 402541128.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821145209) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 569917 + ... + 571355.

It is an arithmetic number, because the mean of its divisors is an integer number (21301280).

Almost surely, 2^821145204 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 821145204, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1150269120).

821145204 is an abundant number, since it is smaller than the sum of its proper divisors (1479393036).

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

821145204 is a wasteful number, since it uses less digits than its factorization.

821145204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1602 (or 1586 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 27.

The square root of 821145204 is about 28655.6312790348. The cubic root of 821145204 is about 936.4256912016.

The spelling of 821145204 in words is "eight hundred twenty-one million, one hundred forty-five thousand, two hundred four".