19743691 has 6 divisors (see below), whose sum is σ = 21701876. Its totient is φ = 17948700.

The previous prime is 19743677. The next prime is 19743767. The reversal of 19743691 is 19634791.

It is not a de Polignac number, because 19743691 - 2¹¹ = 19741643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19743611) 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, 81465 + ... + 81706.

Almost surely, 2^19743691 is an apocalyptic number.

19743691 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

19743691 is a deficient number, since it is larger than the sum of its proper divisors (1958185).

19743691 is a wasteful number, since it uses less digits than its factorization.

19743691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163193 (or 163182 counting only the distinct ones).

The product of its digits is 40824, while the sum is 40.

The square root of 19743691 is about 4443.3873340054. The cubic root of 19743691 is about 270.2772232646.

Subtracting from 19743691 its reverse (19634791), we obtain a square (108900 = 330²).

It can be divided in two parts, 1974 and 3691, that added together give a palindrome (5665).

The spelling of 19743691 in words is "nineteen million, seven hundred forty-three thousand, six hundred ninety-one".