428221525 has 24 divisors (see below), whose sum is σ = 568143200. Its totient is φ = 319204800.

The previous prime is 428221513. The next prime is 428221529. The reversal of 428221525 is 525122824.

It is not a de Polignac number, because 428221525 - 2¹⁵ = 428188757 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (428221529) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21586 + ... + 36364.

Almost surely, 2^428221525 is an apocalyptic number.

It is an amenable number.

428221525 is a deficient number, since it is larger than the sum of its proper divisors (139921675).

428221525 is a wasteful number, since it uses less digits than its factorization.

428221525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14869 (or 14864 counting only the distinct ones).

The product of its digits is 12800, while the sum is 31.

The square root of 428221525 is about 20693.5140805036. The cubic root of 428221525 is about 753.7422005616.

The spelling of 428221525 in words is "four hundred twenty-eight million, two hundred twenty-one thousand, five hundred twenty-five".