19997685 has 48 divisors (see below), whose sum is σ = 36516480. Its totient is φ = 10497600.

The previous prime is 19997683. The next prime is 19997689. The reversal of 19997685 is 58679991.

It is not a de Polignac number, because 19997685 - 2¹ = 19997683 is a prime.

Its product of digits (1224720) is a multiple of the sum of its prime factors (280).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19997683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 132360 + ... + 132510.

It is an arithmetic number, because the mean of its divisors is an integer number (760760).

Almost surely, 2^19997685 is an apocalyptic number.

19997685 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19997685 is a deficient number, since it is larger than the sum of its proper divisors (16518795).

19997685 is a wasteful number, since it uses less digits than its factorization.

19997685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280 (or 268 counting only the distinct ones).

The product of its digits is 1224720, while the sum is 54.

The square root of 19997685 is about 4471.8771226410. The cubic root of 19997685 is about 271.4312881274.

The spelling of 19997685 in words is "nineteen million, nine hundred ninety-seven thousand, six hundred eighty-five".