19997439 has 48 divisors (see below), whose sum is σ = 34473600. Its totient is φ = 10194240.

The previous prime is 19997413. The next prime is 19997441. The reversal of 19997439 is 93479991.

It is not a de Polignac number, because 19997439 - 2⁸ = 19997183 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 19997391 and 19997400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19997459) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 134137 + ... + 134285.

It is an arithmetic number, because the mean of its divisors is an integer number (718200).

Almost surely, 2^19997439 is an apocalyptic number.

19997439 is a deficient number, since it is larger than the sum of its proper divisors (14476161).

19997439 is a wasteful number, since it uses less digits than its factorization.

19997439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 260 (or 253 counting only the distinct ones).

The product of its digits is 551124, while the sum is 51.

The square root of 19997439 is about 4471.8496173284. The cubic root of 19997439 is about 271.4301751257.

The spelling of 19997439 in words is "nineteen million, nine hundred ninety-seven thousand, four hundred thirty-nine".