19998561370 has 32 divisors (see below), whose sum is σ = 36439198848. Its totient is φ = 7901644608.

The previous prime is 19998561367. The next prime is 19998561379. The reversal of 19998561370 is 7316589991.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (19998561379) 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 15 ways as a sum of consecutive naturals, for example, 384457 + ... + 433363.

It is an arithmetic number, because the mean of its divisors is an integer number (1138724964).

Almost surely, 2^19998561370 is an apocalyptic number.

19998561370 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19998561370 is a deficient number, since it is larger than the sum of its proper divisors (16440637478).

19998561370 is a wasteful number, since it uses less digits than its factorization.

19998561370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49414.

The product of its (nonzero) digits is 3674160, while the sum is 58.

The spelling of 19998561370 in words is "nineteen billion, nine hundred ninety-eight million, five hundred sixty-one thousand, three hundred seventy".