521724420 has 432 divisors, whose sum is σ = 2023676928. Its totient is φ = 106375680.

The previous prime is 521724419. The next prime is 521724431. The reversal of 521724420 is 24427125.

521724420 is a `hidden beast` number, since 5 + 217 + 2 + 442 + 0 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 14100642 + ... + 14100678.

Almost surely, 2^521724420 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 521724420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1011838464).

521724420 is an abundant number, since it is smaller than the sum of its proper divisors (1501952508).

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

521724420 is a wasteful number, since it uses less digits than its factorization.

521724420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128 (or 104 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 27.

The square root of 521724420 is about 22841.2876169449. The cubic root of 521724420 is about 805.0330709251.

The spelling of 521724420 in words is "five hundred twenty-one million, seven hundred twenty-four thousand, four hundred twenty".