19965965 has 4 divisors (see below), whose sum is σ = 23959164. Its totient is φ = 15972768.

The previous prime is 19965961. The next prime is 19965997. The reversal of 19965965 is 56956991.

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 15382084 + 4583881 = 3922^2 + 2141^2 .

It is a cyclic number.

It is not a de Polignac number, because 19965965 - 2² = 19965961 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19965961) 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, 1996592 + ... + 1996601.

It is an arithmetic number, because the mean of its divisors is an integer number (5989791).

Almost surely, 2^19965965 is an apocalyptic number.

It is an amenable number.

19965965 is a deficient number, since it is larger than the sum of its proper divisors (3993199).

19965965 is an equidigital number, since it uses as much as digits as its factorization.

19965965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3993198.

The product of its digits is 656100, while the sum is 50.

The square root of 19965965 is about 4468.3291060530. The cubic root of 19965965 is about 271.2876988950.

The spelling of 19965965 in words is "nineteen million, nine hundred sixty-five thousand, nine hundred sixty-five".