19681807 has 8 divisors (see below), whose sum is σ = 21018240. Its totient is φ = 18389280.

The previous prime is 19681789. The next prime is 19681841. The reversal of 19681807 is 70818691.

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

It is a cyclic number.

It is not a de Polignac number, because 19681807 - 2²³ = 11293199 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19681807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19681847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10048 + ... + 11845.

It is an arithmetic number, because the mean of its divisors is an integer number (2627280).

Almost surely, 2^19681807 is an apocalyptic number.

19681807 is a deficient number, since it is larger than the sum of its proper divisors (1336433).

19681807 is a wasteful number, since it uses less digits than its factorization.

19681807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21953.

The product of its (nonzero) digits is 24192, while the sum is 40.

The square root of 19681807 is about 4436.4182625176. The cubic root of 19681807 is about 269.9945449287.

The spelling of 19681807 in words is "nineteen million, six hundred eighty-one thousand, eight hundred seven".