19948809355281 has 9 divisors (see below), whose sum is σ = 28814966200969. Its totient is φ = 13299197304036.

The previous prime is 19948809355199. The next prime is 19948809355283. The reversal of 19948809355281 is 18255390884991.

The square root of 19948809355281 is 4466409.

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

19948809355281 is a `hidden beast` number, since 1 + 9 + 9 + 4 + 8 + 8 + 0 + 93 + 5 + 528 + 1 = 666.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 19948809355281 - 2¹⁷ = 19948809224209 is a prime.

It is a super-2 number, since 2×19948809355281² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19948809355283) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 12654826 + ... + 14143628.

Almost surely, 2^{19948809355281} is an apocalyptic number.

19948809355281 is the 4466409-th square number.

19948809355281 is the 2233205-th centered octagonal number.

It is an amenable number.

19948809355281 is a deficient number, since it is larger than the sum of its proper divisors (8866156845688).

19948809355281 is an frugal number, since it uses more digits than its factorization.

19948809355281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2977612 (or 1488806 counting only the distinct ones).

The product of its (nonzero) digits is 223948800, while the sum is 72.

It can be divided in two parts, 1994880 and 9355281, that added together give a square (11350161 = 3369²).

The spelling of 19948809355281 in words is "nineteen trillion, nine hundred forty-eight billion, eight hundred nine million, three hundred fifty-five thousand, two hundred eighty-one".