19678081 has 2 divisors, whose sum is σ = 19678082. Its totient is φ = 19678080.

The previous prime is 19678079. The next prime is 19678103. The reversal of 19678081 is 18087691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15840400 + 3837681 = 3980^2 + 1959^2 .

It is an emirp because it is prime and its reverse (18087691) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19678081 - 2¹ = 19678079 is a prime.

It is a super-2 number, since 2×19678081² = 774453743685122, which contains 22 as substring.

Together with 19678079, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (19678181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9839040 + 9839041.

It is an arithmetic number, because the mean of its divisors is an integer number (9839041).

Almost surely, 2^19678081 is an apocalyptic number.

It is an amenable number.

19678081 is a deficient number, since it is larger than the sum of its proper divisors (1).

19678081 is an equidigital number, since it uses as much as digits as its factorization.

19678081 is an odious number, because the sum of its binary digits is odd.

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

The square root of 19678081 is about 4435.9983092873. The cubic root of 19678081 is about 269.9775061279.

The spelling of 19678081 in words is "nineteen million, six hundred seventy-eight thousand, eighty-one".