19890066938 has 32 divisors (see below), whose sum is σ = 34447106304. Its totient is φ = 8436943872.

The previous prime is 19890066869. The next prime is 19890066941. The reversal of 19890066938 is 83966009891.

It is a super-2 number, since 2×19890066938² (a number of 21 digits) contains 22 as substring.

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 15 ways as a sum of consecutive naturals, for example, 4521356 + ... + 4525752.

It is an arithmetic number, because the mean of its divisors is an integer number (1076472072).

Almost surely, 2^19890066938 is an apocalyptic number.

19890066938 is a deficient number, since it is larger than the sum of its proper divisors (14557039366).

19890066938 is a wasteful number, since it uses less digits than its factorization.

19890066938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7646.

The product of its (nonzero) digits is 5038848, while the sum is 59.

The spelling of 19890066938 in words is "nineteen billion, eight hundred ninety million, sixty-six thousand, nine hundred thirty-eight".