19840681 has 8 divisors (see below), whose sum is σ = 22930560. Its totient is φ = 16814688.

The previous prime is 19840663. The next prime is 19840687. The reversal of 19840681 is 18604891.

It is a happy number.

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 19840681 - 2²³ = 11452073 is a prime.

It is a super-2 number, since 2×19840681² = 787305245087522, which contains 22 as substring.

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 19840681.

It is not an unprimeable number, because it can be changed into a prime (19840687) 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, 15301 + ... + 16546.

It is an arithmetic number, because the mean of its divisors is an integer number (2866320).

Almost surely, 2^19840681 is an apocalyptic number.

It is an amenable number.

19840681 is a deficient number, since it is larger than the sum of its proper divisors (3089879).

19840681 is an equidigital number, since it uses as much as digits as its factorization.

19840681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31943.

The product of its (nonzero) digits is 13824, while the sum is 37.

The square root of 19840681 is about 4454.2879341147. The cubic root of 19840681 is about 270.7190754544.

The spelling of 19840681 in words is "nineteen million, eight hundred forty thousand, six hundred eighty-one".