1603281681 has 21 divisors (see below), whose sum is σ = 2405444889. Its totient is φ = 1068133716.

The previous prime is 1603281613. The next prime is 1603281697. The reversal of 1603281681 is 1861823061.

The square root of 1603281681 is 40041.

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

It is not a de Polignac number, because 1603281681 - 2¹¹ = 1603279633 is a prime.

It is a super-2 number, since 2×1603281681² = 5141024297260371522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1603285681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 1080366 + ... + 1081848.

Almost surely, 2^1603281681 is an apocalyptic number.

1603281681 is the 40041-st square number.

1603281681 is the 20021-st centered octagonal number.

It is an amenable number.

1603281681 is a deficient number, since it is larger than the sum of its proper divisors (802163208).

1603281681 is an frugal number, since it uses more digits than its factorization.

1603281681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2984 (or 1486 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The cubic root of 1603281681 is about 1170.4061903270.

Multiplying 1603281681 by its sum of digits (36), we get a square (57718140516 = 240246²).

The spelling of 1603281681 in words is "one billion, six hundred three million, two hundred eighty-one thousand, six hundred eighty-one".