19986538 has 24 divisors (see below), whose sum is σ = 35493444. Its totient is φ = 8384640.

The previous prime is 19986523. The next prime is 19986541. The reversal of 19986538 is 83568991.

It can be written as a sum of positive squares in 2 ways, for example, as 19070689 + 915849 = 4367^2 + 957^2 .

It is a junction number, because it is equal to n+sod(n) for n = 19986491 and 19986500.

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, 31 + ... + 6322.

Almost surely, 2^19986538 is an apocalyptic number.

19986538 is a deficient number, since it is larger than the sum of its proper divisors (15506906).

19986538 is a wasteful number, since it uses less digits than its factorization.

19986538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6390 (or 6379 counting only the distinct ones).

The product of its digits is 466560, while the sum is 49.

The square root of 19986538 is about 4470.6306042884. The cubic root of 19986538 is about 271.3808455066.

The spelling of 19986538 in words is "nineteen million, nine hundred eighty-six thousand, five hundred thirty-eight".