19988565 has 8 divisors (see below), whose sum is σ = 31981728. Its totient is φ = 10660560.

The previous prime is 19988543. The next prime is 19988567. The reversal of 19988565 is 56588991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 19988565 - 2⁵ = 19988533 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19988567) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 666271 + ... + 666300.

It is an arithmetic number, because the mean of its divisors is an integer number (3997716).

Almost surely, 2^19988565 is an apocalyptic number.

19988565 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19988565 is a deficient number, since it is larger than the sum of its proper divisors (11993163).

19988565 is a wasteful number, since it uses less digits than its factorization.

19988565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1332579.

The product of its digits is 777600, while the sum is 51.

The square root of 19988565 is about 4470.8573003396. The cubic root of 19988565 is about 271.3900195213.

The spelling of 19988565 in words is "nineteen million, nine hundred eighty-eight thousand, five hundred sixty-five".