428945521 has 9 divisors (see below), whose sum is σ = 434972811. Its totient is φ = 423001464.

The previous prime is 428945519. The next prime is 428945527. The reversal of 428945521 is 125549824.

It is a happy number.

The square root of 428945521 is 20711.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 50253921 + 378691600 = 7089^2 + 19460^2 .

It is not a de Polignac number, because 428945521 - 2¹ = 428945519 is a prime.

It is a super-2 number, since 2×428945521² = 367988519971922882, which contains 22 as substring.

It is a Duffinian number.

Its product of digits (115200) is a multiple of the sum of its prime divisors (288).

It is not an unprimeable number, because it can be changed into a prime (428945527) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2878755 + ... + 2878903.

Almost surely, 2^428945521 is an apocalyptic number.

428945521 is the 20711-st square number.

428945521 is the 10356-th centered octagonal number.

It is an amenable number.

428945521 is a deficient number, since it is larger than the sum of its proper divisors (6027290).

428945521 is an frugal number, since it uses more digits than its factorization.

428945521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 576 (or 288 counting only the distinct ones).

The product of its digits is 115200, while the sum is 40.

The cubic root of 428945521 is about 754.1667464661.

The spelling of 428945521 in words is "four hundred twenty-eight million, nine hundred forty-five thousand, five hundred twenty-one".