521540844 has 48 divisors (see below), whose sum is σ = 1335035520. Its totient is φ = 157152640.

The previous prime is 521540839. The next prime is 521540881. The reversal of 521540844 is 448045125.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12592 + ... + 34664.

It is an arithmetic number, because the mean of its divisors is an integer number (27813240).

Almost surely, 2^521540844 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 521540844, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (667517760).

521540844 is an abundant number, since it is smaller than the sum of its proper divisors (813494676).

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

521540844 is a wasteful number, since it uses less digits than its factorization.

521540844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22270 (or 22268 counting only the distinct ones).

The product of its (nonzero) digits is 25600, while the sum is 33.

The square root of 521540844 is about 22837.2687508817. The cubic root of 521540844 is about 804.9386391510.

Adding to 521540844 its reverse (448045125), we get a palindrome (969585969).

The spelling of 521540844 in words is "five hundred twenty-one million, five hundred forty thousand, eight hundred forty-four".