19666531028 has 24 divisors (see below), whose sum is σ = 34988427264. Its totient is φ = 9669909600.

The previous prime is 19666531013. The next prime is 19666531033. The reversal of 19666531028 is 82013566691.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 2150201 + ... + 2159327.

It is an arithmetic number, because the mean of its divisors is an integer number (1457851136).

Almost surely, 2^19666531028 is an apocalyptic number.

It is an amenable number.

19666531028 is a deficient number, since it is larger than the sum of its proper divisors (15321896236).

19666531028 is a wasteful number, since it uses less digits than its factorization.

19666531028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18023 (or 18021 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 47.

The spelling of 19666531028 in words is "nineteen billion, six hundred sixty-six million, five hundred thirty-one thousand, twenty-eight".