428538665 has 4 divisors (see below), whose sum is σ = 514246404. Its totient is φ = 342830928.

The previous prime is 428538661. The next prime is 428538697. The reversal of 428538665 is 566835824.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 110166016 + 318372649 = 10496^2 + 17843^2 .

It is a cyclic number.

It is not a de Polignac number, because 428538665 - 2² = 428538661 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (428538661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42853862 + ... + 42853871.

It is an arithmetic number, because the mean of its divisors is an integer number (128561601).

Almost surely, 2^428538665 is an apocalyptic number.

It is an amenable number.

428538665 is a deficient number, since it is larger than the sum of its proper divisors (85707739).

428538665 is an equidigital number, since it uses as much as digits as its factorization.

428538665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85707738.

The product of its digits is 1382400, while the sum is 47.

The square root of 428538665 is about 20701.1754497178. The cubic root of 428538665 is about 753.9282279644.

The spelling of 428538665 in words is "four hundred twenty-eight million, five hundred thirty-eight thousand, six hundred sixty-five".