19985279243 has 2 divisors, whose sum is σ = 19985279244. Its totient is φ = 19985279242.

The previous prime is 19985279239. The next prime is 19985279263. The reversal of 19985279243 is 34297258991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19985279243 - 2² = 19985279239 is a prime.

It is a super-2 number, since 2×19985279243² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (19985279263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9992639621 + 9992639622.

It is an arithmetic number, because the mean of its divisors is an integer number (9992639622).

Almost surely, 2^19985279243 is an apocalyptic number.

19985279243 is a deficient number, since it is larger than the sum of its proper divisors (1).

19985279243 is an equidigital number, since it uses as much as digits as its factorization.

19985279243 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9797760, while the sum is 59.

The spelling of 19985279243 in words is "nineteen billion, nine hundred eighty-five million, two hundred seventy-nine thousand, two hundred forty-three".