1908428968681 has 3 divisors (see below), whose sum is σ = 1908430350141. Its totient is φ = 1908427587222.

The previous prime is 1908428968669. The next prime is 1908428968687. The reversal of 1908428968681 is 1868698248091.

The square root of 1908428968681 is 1381459.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 1908428968681 - 2³⁹ = 1358673154793 is a prime.

It is a super-2 number, since 2×1908428968681² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1908428968681.

It is not an unprimeable number, because it can be changed into a prime (1908428968687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 690730 + ... + 2072188.

It is an arithmetic number, because the mean of its divisors is an integer number (636143450047).

Almost surely, 2^{1908428968681} is an apocalyptic number.

1908428968681 is the 1381459-th square number.

1908428968681 is the 690730-th centered octagonal number.

It is an amenable number.

1908428968681 is a deficient number, since it is larger than the sum of its proper divisors (1381460).

1908428968681 is an frugal number, since it uses more digits than its factorization.

1908428968681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2762918 (or 1381459 counting only the distinct ones).

The product of its (nonzero) digits is 95551488, while the sum is 70.

The spelling of 1908428968681 in words is "one trillion, nine hundred eight billion, four hundred twenty-eight million, nine hundred sixty-eight thousand, six hundred eighty-one".