428138665 has 8 divisors (see below), whose sum is σ = 515972808. Its totient is φ = 341040000.

The previous prime is 428138639. The next prime is 428138671. The reversal of 428138665 is 566831824.

It can be written as a sum of positive squares in 4 ways, for example, as 21874329 + 406264336 = 4677^2 + 20156^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 428138665 - 2¹¹ = 428136617 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 182586 + ... + 184915.

It is an arithmetic number, because the mean of its divisors is an integer number (64496601).

Almost surely, 2^428138665 is an apocalyptic number.

It is an amenable number.

428138665 is a deficient number, since it is larger than the sum of its proper divisors (87834143).

428138665 is a wasteful number, since it uses less digits than its factorization.

428138665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 367739.

The product of its digits is 276480, while the sum is 43.

The square root of 428138665 is about 20691.5119070599. The cubic root of 428138665 is about 753.6935815612.

The spelling of 428138665 in words is "four hundred twenty-eight million, one hundred thirty-eight thousand, six hundred sixty-five".