19946781558 has 48 divisors (see below), whose sum is σ = 47211602256. Its totient is φ = 6036189120.

The previous prime is 19946781551. The next prime is 19946781601. The reversal of 19946781558 is 85518764991.

19946781558 is a `hidden beast` number, since 1 + 9 + 9 + 4 + 6 + 78 + 1 + 558 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 19946781495 and 19946781504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19946781551) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 76416 + ... + 213852.

It is an arithmetic number, because the mean of its divisors is an integer number (983575047).

Almost surely, 2^19946781558 is an apocalyptic number.

19946781558 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

19946781558 is an abundant number, since it is smaller than the sum of its proper divisors (27264820698).

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

19946781558 is a wasteful number, since it uses less digits than its factorization.

19946781558 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138189 (or 138186 counting only the distinct ones).

The product of its digits is 21772800, while the sum is 63.

The spelling of 19946781558 in words is "nineteen billion, nine hundred forty-six million, seven hundred eighty-one thousand, five hundred fifty-eight".