19928665 has 8 divisors (see below), whose sum is σ = 24497928. Its totient is φ = 15553920.

The previous prime is 19928653. The next prime is 19928677. The reversal of 19928665 is 56682991.

It is an interprime number because it is at equal distance from previous prime (19928653) and next prime (19928677).

It can be written as a sum of positive squares in 4 ways, for example, as 1369 + 19927296 = 37^2 + 4464^2 .

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

It is not a de Polignac number, because 19928665 - 2⁵ = 19928633 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, 48402 + ... + 48811.

It is an arithmetic number, because the mean of its divisors is an integer number (3062241).

Almost surely, 2^19928665 is an apocalyptic number.

It is an amenable number.

19928665 is a deficient number, since it is larger than the sum of its proper divisors (4569263).

19928665 is an equidigital number, since it uses as much as digits as its factorization.

19928665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97259.

The product of its digits is 233280, while the sum is 46.

The square root of 19928665 is about 4464.1533351801. The cubic root of 19928665 is about 271.1186555738.

The spelling of 19928665 in words is "nineteen million, nine hundred twenty-eight thousand, six hundred sixty-five".