19721250907 has 2 divisors, whose sum is σ = 19721250908. Its totient is φ = 19721250906.

The previous prime is 19721250889. The next prime is 19721250919. The reversal of 19721250907 is 70905212791.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19721250907 - 2⁷ = 19721250779 is a prime.

It is a super-3 number, since 3×19721250907³ (a number of 32 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (19721250947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9860625453 + 9860625454.

It is an arithmetic number, because the mean of its divisors is an integer number (9860625454).

Almost surely, 2^19721250907 is an apocalyptic number.

19721250907 is a deficient number, since it is larger than the sum of its proper divisors (1).

19721250907 is an equidigital number, since it uses as much as digits as its factorization.

19721250907 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 79380, while the sum is 43.

The spelling of 19721250907 in words is "nineteen billion, seven hundred twenty-one million, two hundred fifty thousand, nine hundred seven".