19991373 has 16 divisors (see below), whose sum is σ = 27795456. Its totient is φ = 12766320.

The previous prime is 19991357. The next prime is 19991381. The reversal of 19991373 is 37319991.

It is not a de Polignac number, because 19991373 - 2⁴ = 19991357 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19991333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8536 + ... + 10622.

It is an arithmetic number, because the mean of its divisors is an integer number (1737216).

Almost surely, 2^19991373 is an apocalyptic number.

It is an amenable number.

19991373 is a deficient number, since it is larger than the sum of its proper divisors (7804083).

19991373 is a wasteful number, since it uses less digits than its factorization.

19991373 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2224.

The product of its digits is 45927, while the sum is 42.

The square root of 19991373 is about 4471.1713230428. The cubic root of 19991373 is about 271.4027272452.

The spelling of 19991373 in words is "nineteen million, nine hundred ninety-one thousand, three hundred seventy-three".