438725521 has 10 divisors (see below), whose sum is σ = 475315642. Its totient is φ = 404951040.

The previous prime is 438725509. The next prime is 438725531. The reversal of 438725521 is 125527834.

It can be written as a sum of positive squares in 5 ways, for example, as 324000000 + 114725521 = 18000^2 + 10711^2 .

It is not a de Polignac number, because 438725521 - 2⁷ = 438725393 is a prime.

It is a super-3 number, since 3×438725521³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (438725531) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 20881 + ... + 36241.

Almost surely, 2^438725521 is an apocalyptic number.

It is an amenable number.

438725521 is a deficient number, since it is larger than the sum of its proper divisors (36590121).

438725521 is an frugal number, since it uses more digits than its factorization.

438725521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15413 (or 15374 counting only the distinct ones).

The product of its digits is 67200, while the sum is 37.

The square root of 438725521 is about 20945.7757316362. The cubic root of 438725521 is about 759.8554209048.

The spelling of 438725521 in words is "four hundred thirty-eight million, seven hundred twenty-five thousand, five hundred twenty-one".