16490981906281 has 9 divisors (see below), whose sum is σ = 17518175222149. Its totient is φ = 15520859172544.

The previous prime is 16490981906227. The next prime is 16490981906293. The reversal of 16490981906281 is 18260918909461.

The square root of 16490981906281 is 4060909.

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

It can be written as a sum of positive squares in 4 ways, for example, as 1652615662681 + 14838366243600 = 1285541^2 + 3852060^2 .

It is not a de Polignac number, because 16490981906281 - 2¹⁹ = 16490981381993 is a prime.

It is a super-2 number, since 2×16490981906281² (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 (16490981904281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 68916015 + ... + 69154891.

Almost surely, 2^{16490981906281} is an apocalyptic number.

16490981906281 is the 4060909-th square number.

16490981906281 is the 2030455-th centered octagonal number.

It is an amenable number.

16490981906281 is a deficient number, since it is larger than the sum of its proper divisors (1027193315868).

16490981906281 is an frugal number, since it uses more digits than its factorization.

16490981906281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 477788 (or 238894 counting only the distinct ones).

The product of its (nonzero) digits is 13436928, while the sum is 64.

The spelling of 16490981906281 in words is "sixteen trillion, four hundred ninety billion, nine hundred eighty-one million, nine hundred six thousand, two hundred eighty-one".