19666356228 has 96 divisors (see below), whose sum is σ = 55727723520. Its totient is φ = 5970792960.

The previous prime is 19666356221. The next prime is 19666356247. The reversal of 19666356228 is 82265366691.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (19666356221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 115851 + ... + 229682.

It is an arithmetic number, because the mean of its divisors is an integer number (580497120).

Almost surely, 2^19666356228 is an apocalyptic number.

19666356228 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

19666356228 is an abundant number, since it is smaller than the sum of its proper divisors (36061367292).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19666356228 is a wasteful number, since it uses less digits than its factorization.

19666356228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345594 (or 345586 counting only the distinct ones).

The product of its digits is 5598720, while the sum is 54.

The spelling of 19666356228 in words is "nineteen billion, six hundred sixty-six million, three hundred fifty-six thousand, two hundred twenty-eight".