19981207 has 2 divisors, whose sum is σ = 19981208. Its totient is φ = 19981206.

The previous prime is 19981201. The next prime is 19981223. The reversal of 19981207 is 70218991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19981207 - 2⁷ = 19981079 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19981201) 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 as a sum of consecutive naturals, namely, 9990603 + 9990604.

It is an arithmetic number, because the mean of its divisors is an integer number (9990604).

Almost surely, 2^19981207 is an apocalyptic number.

19981207 is a deficient number, since it is larger than the sum of its proper divisors (1).

19981207 is an equidigital number, since it uses as much as digits as its factorization.

19981207 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 19981207 is about 4470.0343399128. The cubic root of 19981207 is about 271.3567149321.

It can be divided in two parts, 199 and 81207, that added together give a triangular number (81406 = T₄₀₃).

The spelling of 19981207 in words is "nineteen million, nine hundred eighty-one thousand, two hundred seven".