19691965 has 4 divisors (see below), whose sum is σ = 23630364. Its totient is φ = 15753568.

The previous prime is 19691963. The next prime is 19691977. The reversal of 19691965 is 56919691.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56919691 = 109 ⋅522199.

It can be written as a sum of positive squares in 2 ways, for example, as 8415801 + 11276164 = 2901^2 + 3358^2 .

It is a cyclic number.

It is not a de Polignac number, because 19691965 - 2¹ = 19691963 is a prime.

It is a super-2 number, since 2×19691965² = 775546971122450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19691963) 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, 1969192 + ... + 1969201.

It is an arithmetic number, because the mean of its divisors is an integer number (5907591).

Almost surely, 2^19691965 is an apocalyptic number.

It is an amenable number.

19691965 is a deficient number, since it is larger than the sum of its proper divisors (3938399).

19691965 is an equidigital number, since it uses as much as digits as its factorization.

19691965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3938398.

The product of its digits is 131220, while the sum is 46.

The square root of 19691965 is about 4437.5629572999. The cubic root of 19691965 is about 270.0409860048.

The spelling of 19691965 in words is "nineteen million, six hundred ninety-one thousand, nine hundred sixty-five".