521403540 has 48 divisors (see below), whose sum is σ = 1668492672. Its totient is φ = 119177856.

The previous prime is 521403527. The next prime is 521403569. The reversal of 521403540 is 45304125.

It is a self number, because there is not a number n which added to its sum of digits gives 521403540.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 620299 + ... + 621138.

It is an arithmetic number, because the mean of its divisors is an integer number (34760264).

Almost surely, 2^521403540 is an apocalyptic number.

It is an amenable number.

521403540 is an abundant number, since it is smaller than the sum of its proper divisors (1147089132).

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

521403540 is a wasteful number, since it uses less digits than its factorization.

521403540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1241456 (or 1241454 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 521403540 is about 22834.2624141880. The cubic root of 521403540 is about 804.8679952781.

Adding to 521403540 its reverse (45304125), we get a palindrome (566707665).

The spelling of 521403540 in words is "five hundred twenty-one million, four hundred three thousand, five hundred forty".