19997311 has 6 divisors (see below), whose sum is σ = 20161400. Its totient is φ = 19834056.

The previous prime is 19997297. The next prime is 19997317. The reversal of 19997311 is 11379991.

It is not a de Polignac number, because 19997311 - 2⁷ = 19997183 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 (19997317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 62925 + ... + 63241.

Almost surely, 2^19997311 is an apocalyptic number.

19997311 is a deficient number, since it is larger than the sum of its proper divisors (164089).

19997311 is an frugal number, since it uses more digits than its factorization.

19997311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 833 (or 516 counting only the distinct ones).

The product of its digits is 15309, while the sum is 40.

The square root of 19997311 is about 4471.8353055541. The cubic root of 19997311 is about 271.4295959993.

The spelling of 19997311 in words is "nineteen million, nine hundred ninety-seven thousand, three hundred eleven".