19966019 has 4 divisors (see below), whose sum is σ = 20085744. Its totient is φ = 19846296.

The previous prime is 19965997. The next prime is 19966021. The reversal of 19966019 is 91066991.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 19966019 - 2⁸ = 19965763 is a prime.

It is a super-2 number, since 2×19966019² = 797283829416722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19966049) 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, 59612 + ... + 59945.

It is an arithmetic number, because the mean of its divisors is an integer number (5021436).

Almost surely, 2^19966019 is an apocalyptic number.

19966019 is a deficient number, since it is larger than the sum of its proper divisors (119725).

19966019 is a wasteful number, since it uses less digits than its factorization.

19966019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119724.

The product of its (nonzero) digits is 26244, while the sum is 41.

The square root of 19966019 is about 4468.3351485760. The cubic root of 19966019 is about 271.2879434699.

The spelling of 19966019 in words is "nineteen million, nine hundred sixty-six thousand, nineteen".