521388 has 36 divisors (see below), whose sum is σ = 1506960. Its totient is φ = 148896.

The previous prime is 521377. The next prime is 521393. The reversal of 521388 is 883125.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 521388.

It is an unprimeable number.

521388 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 783 + ... + 1286.

It is an arithmetic number, because the mean of its divisors is an integer number (41860).

2⁵²¹³⁸⁸ is an apocalyptic number.

It is an amenable number.

521388 is an abundant number, since it is smaller than the sum of its proper divisors (985572).

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

521388 is a wasteful number, since it uses less digits than its factorization.

521388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2086 (or 2081 counting only the distinct ones).

The product of its digits is 1920, while the sum is 27.

The square root of 521388 is about 722.0720185688. The cubic root of 521388 is about 80.4859999058.

It can be divided in two parts, 521 and 388, that added together give a palindrome (909).

The spelling of 521388 in words is "five hundred twenty-one thousand, three hundred eighty-eight".