19850555664 has 135 divisors (see below), whose sum is σ = 56796942423. Its totient is φ = 6472014912.

The previous prime is 19850555657. The next prime is 19850555671. The reversal of 19850555664 is 46655505891.

The square root of 19850555664 is 140892.

It is a perfect power (a square), and thus also a powerful number.

19850555664 is a `hidden beast` number, since 1 + 9 + 85 + 0 + 5 + 556 + 6 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (19850555657) and next prime (19850555671).

It is a self number, because there is not a number n which added to its sum of digits gives 19850555664.

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 26 ways as a sum of consecutive naturals, for example, 99751437 + ... + 99751635.

Almost surely, 2^19850555664 is an apocalyptic number.

19850555664 is the 140892-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19850555664

19850555664 is an abundant number, since it is smaller than the sum of its proper divisors (36946386759).

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

19850555664 is an equidigital number, since it uses as much as digits as its factorization.

19850555664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 530 (or 263 counting only the distinct ones).

The product of its (nonzero) digits is 6480000, while the sum is 54.

The spelling of 19850555664 in words is "nineteen billion, eight hundred fifty million, five hundred fifty-five thousand, six hundred sixty-four".