19866361449 has 32 divisors (see below), whose sum is σ = 32206671360. Its totient is φ = 10735545600.

The previous prime is 19866361399. The next prime is 19866361457. The reversal of 19866361449 is 94416366891.

It is not a de Polignac number, because 19866361449 - 2¹² = 19866357353 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (19866371449) 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 in 31 ways as a sum of consecutive naturals, for example, 921247 + ... + 942564.

It is an arithmetic number, because the mean of its divisors is an integer number (1006458480).

Almost surely, 2^19866361449 is an apocalyptic number.

19866361449 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

19866361449 is a deficient number, since it is larger than the sum of its proper divisors (12340309911).

19866361449 is a wasteful number, since it uses less digits than its factorization.

19866361449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1863861.

The product of its digits is 6718464, while the sum is 57.

The spelling of 19866361449 in words is "nineteen billion, eight hundred sixty-six million, three hundred sixty-one thousand, four hundred forty-nine".