1908606681 has 12 divisors (see below), whose sum is σ = 2794642708. Its totient is φ = 1254973824.

The previous prime is 1908606671. The next prime is 1908606697. The reversal of 1908606681 is 1866068091.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 902702025 + 1005904656 = 30045^2 + 31716^2 .

It is not a de Polignac number, because 1908606681 - 2⁶ = 1908606617 is a prime.

It is a super-2 number, since 2×1908606681² = 7285558925515671522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1908606641) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1451860 + ... + 1453173.

Almost surely, 2^1908606681 is an apocalyptic number.

It is an amenable number.

1908606681 is a deficient number, since it is larger than the sum of its proper divisors (886036027).

1908606681 is a wasteful number, since it uses less digits than its factorization.

1908606681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2905112 (or 2905109 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The square root of 1908606681 is about 43687.6032874316. The cubic root of 1908606681 is about 1240.4296726802.

The spelling of 1908606681 in words is "one billion, nine hundred eight million, six hundred six thousand, six hundred eighty-one".