20686919 has 8 divisors (see below), whose sum is σ = 23118480. Its totient is φ = 18347200.

The previous prime is 20686901. The next prime is 20686927. The reversal of 20686919 is 91968602.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20686919 is a prime.

It is a super-2 number, since 2×20686919² = 855897235425122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20686949) 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 7 ways as a sum of consecutive naturals, for example, 22484 + ... + 23385.

It is an arithmetic number, because the mean of its divisors is an integer number (2889810).

Almost surely, 2^20686919 is an apocalyptic number.

20686919 is a deficient number, since it is larger than the sum of its proper divisors (2431561).

20686919 is a wasteful number, since it uses less digits than its factorization.

20686919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45921.

The product of its (nonzero) digits is 46656, while the sum is 41.

The square root of 20686919 is about 4548.2874799203. The cubic root of 20686919 is about 274.5144887912.

The spelling of 20686919 in words is "twenty million, six hundred eighty-six thousand, nine hundred nineteen".