981888755409 has 27 divisors (see below), whose sum is σ = 1423234671313. Its totient is φ = 652315408512.

The previous prime is 981888755399. The next prime is 981888755413. The reversal of 981888755409 is 904557888189.

The square root of 981888755409 is 990903.

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

981888755409 is a `hidden beast` number, since 9 + 8 + 1 + 8 + 8 + 8 + 75 + 540 + 9 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 127558265409 + 854330490000 = 357153^2 + 924300^2 .

It is not a de Polignac number, because 981888755409 - 2³³ = 973298820817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (981888755429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1655798617 + ... + 1655799209.

Almost surely, 2^981888755409 is an apocalyptic number.

981888755409 is the 990903-rd square number.

981888755409 is the 495452-nd centered octagonal number.

It is an amenable number.

981888755409 is a deficient number, since it is larger than the sum of its proper divisors (441345915904).

981888755409 is an frugal number, since it uses more digits than its factorization.

981888755409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2306 (or 1153 counting only the distinct ones).

The product of its (nonzero) digits is 232243200, while the sum is 72.

The spelling of 981888755409 in words is "nine hundred eighty-one billion, eight hundred eighty-eight million, seven hundred fifty-five thousand, four hundred nine".