19686438 has 24 divisors (see below), whose sum is σ = 43171128. Its totient is φ = 6482592.

The previous prime is 19686427. The next prime is 19686463. The reversal of 19686438 is 83468691.

It is a super-2 number, since 2×19686438² = 775111682255688, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 19686393 and 19686402.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5095 + ... + 8082.

It is an arithmetic number, because the mean of its divisors is an integer number (1798797).

Almost surely, 2^19686438 is an apocalyptic number.

19686438 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

19686438 is an abundant number, since it is smaller than the sum of its proper divisors (23484690).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19686438 is a wasteful number, since it uses less digits than its factorization.

19686438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13268 (or 13265 counting only the distinct ones).

The product of its digits is 248832, while the sum is 45.

The square root of 19686438 is about 4436.9401618683. The cubic root of 19686438 is about 270.0157192494.

The spelling of 19686438 in words is "nineteen million, six hundred eighty-six thousand, four hundred thirty-eight".