521421520 has 40 divisors (see below), whose sum is σ = 1217422080. Its totient is φ = 207688320.

The previous prime is 521421517. The next prime is 521421529. The reversal of 521421520 is 25124125.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×521421520² = 543760803038220800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 521421491 and 521421500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521421529) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5485 + ... + 32755.

It is an arithmetic number, because the mean of its divisors is an integer number (30435552).

Almost surely, 2^521421520 is an apocalyptic number.

It is an amenable number.

521421520 is an abundant number, since it is smaller than the sum of its proper divisors (696000560).

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

521421520 is a wasteful number, since it uses less digits than its factorization.

521421520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27523 (or 27517 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 22.

The square root of 521421520 is about 22834.6561174019. The cubic root of 521421520 is about 804.8772468201.

Adding to 521421520 its reverse (25124125), we get a palindrome (546545645).

The spelling of 521421520 in words is "five hundred twenty-one million, four hundred twenty-one thousand, five hundred twenty".