19897065 has 12 divisors (see below), whose sum is σ = 34488324. Its totient is φ = 10611744.

The previous prime is 19897063. The next prime is 19897067. The reversal of 19897065 is 56079891.

It is an interprime number because it is at equal distance from previous prime (19897063) and next prime (19897067).

It can be written as a sum of positive squares in 2 ways, for example, as 5517801 + 14379264 = 2349^2 + 3792^2 .

It is not a de Polignac number, because 19897065 - 2¹ = 19897063 is a prime.

It is a super-2 number, since 2×19897065² = 791786391228450, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 442157 = 19897065 / (1 + 9 + 8 + 9 + 7 + 0 + 6 + 5).

It is a self number, because there is not a number n which added to its sum of digits gives 19897065.

It is not an unprimeable number, because it can be changed into a prime (19897061) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 221034 + ... + 221123.

It is an arithmetic number, because the mean of its divisors is an integer number (2874027).

Almost surely, 2^19897065 is an apocalyptic number.

19897065 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19897065 is a deficient number, since it is larger than the sum of its proper divisors (14591259).

19897065 is a wasteful number, since it uses less digits than its factorization.

19897065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 442168 (or 442165 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 45.

The square root of 19897065 is about 4460.6126260862. The cubic root of 19897065 is about 270.9752794905.

The spelling of 19897065 in words is "nineteen million, eight hundred ninety-seven thousand, sixty-five".