521540012 has 48 divisors (see below), whose sum is σ = 1094166528. Its totient is φ = 212829120.

The previous prime is 521540003. The next prime is 521540023. The reversal of 521540012 is 210045125.

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, 43337 + ... + 54047.

It is an arithmetic number, because the mean of its divisors is an integer number (22795136).

Almost surely, 2^521540012 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 521540012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (547083264).

521540012 is an abundant number, since it is smaller than the sum of its proper divisors (572626516).

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

521540012 is a wasteful number, since it uses less digits than its factorization.

521540012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10806 (or 10804 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 521540012 is about 22837.2505350360. The cubic root of 521540012 is about 804.9382111184.

Adding to 521540012 its reverse (210045125), we get a palindrome (731585137).

The spelling of 521540012 in words is "five hundred twenty-one million, five hundred forty thousand, twelve".