19998747 has 12 divisors (see below), whose sum is σ = 28974400. Its totient is φ = 13292208.

The previous prime is 19998743. The next prime is 19998757. The reversal of 19998747 is 74789991.

It is not a de Polignac number, because 19998747 - 2² = 19998743 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19998693 and 19998702.

It is not an unprimeable number, because it can be changed into a prime (19998743) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 43 + ... + 6324.

Almost surely, 2^19998747 is an apocalyptic number.

19998747 is a deficient number, since it is larger than the sum of its proper divisors (8975653).

19998747 is a wasteful number, since it uses less digits than its factorization.

19998747 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6722 (or 6719 counting only the distinct ones).

The product of its digits is 1143072, while the sum is 54.

The square root of 19998747 is about 4471.9958631466. The cubic root of 19998747 is about 271.4360929323.

The spelling of 19998747 in words is "nineteen million, nine hundred ninety-eight thousand, seven hundred forty-seven".