19891671360064 has 189 divisors, whose sum is σ = 46597358441241. Its totient is φ = 8400514268160.

The previous prime is 19891671360047. The next prime is 19891671360079. The reversal of 19891671360064 is 46006317619891.

The square root of 19891671360064 is 4460008.

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

It can be written as a sum of positive squares in only one way, i.e., 11291481678400 + 8600189681664 = 3360280^2 + 2932608^2 .

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19891671359984 and 19891671360011.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 18232512159 + ... + 18232513249.

Almost surely, 2^{19891671360064} is an apocalyptic number.

19891671360064 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

19891671360064 is the 4460008-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19891671360064

19891671360064 is an abundant number, since it is smaller than the sum of its proper divisors (26705687081177).

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

19891671360064 is an frugal number, since it uses more digits than its factorization.

19891671360064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2354 (or 1173 counting only the distinct ones).

The product of its (nonzero) digits is 11757312, while the sum is 61.

The spelling of 19891671360064 in words is "nineteen trillion, eight hundred ninety-one billion, six hundred seventy-one million, three hundred sixty thousand, sixty-four".