19666749394 has 8 divisors (see below), whose sum is σ = 29663108748. Its totient is φ = 9779046480.

The previous prime is 19666749371. The next prime is 19666749397. The reversal of 19666749394 is 49394766691.

It can be written as a sum of positive squares in 2 ways, for example, as 14666421025 + 5000328369 = 121105^2 + 70713^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (19666749397) 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 in 3 ways as a sum of consecutive naturals, for example, 27163657 + ... + 27164380.

Almost surely, 2^19666749394 is an apocalyptic number.

19666749394 is a deficient number, since it is larger than the sum of its proper divisors (9996359354).

19666749394 is a wasteful number, since it uses less digits than its factorization.

19666749394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54328220.

The product of its digits is 52907904, while the sum is 64.

The spelling of 19666749394 in words is "nineteen billion, six hundred sixty-six million, seven hundred forty-nine thousand, three hundred ninety-four".