19997715 has 8 divisors (see below), whose sum is σ = 31996368. Its totient is φ = 10665440.

The previous prime is 19997713. The next prime is 19997717. The reversal of 19997715 is 51779991.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (19997713) and next prime (19997717).

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

It is not a de Polignac number, because 19997715 - 2¹ = 19997713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19997711) 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, 666576 + ... + 666605.

It is an arithmetic number, because the mean of its divisors is an integer number (3999546).

Almost surely, 2^19997715 is an apocalyptic number.

19997715 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

19997715 is a deficient number, since it is larger than the sum of its proper divisors (11998653).

19997715 is a wasteful number, since it uses less digits than its factorization.

19997715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1333189.

The product of its digits is 178605, while the sum is 48.

The square root of 19997715 is about 4471.8804769358. The cubic root of 19997715 is about 271.4314238587.

The spelling of 19997715 in words is "nineteen million, nine hundred ninety-seven thousand, seven hundred fifteen".