1641278817 has 6 divisors (see below), whose sum is σ = 2370736082. Its totient is φ = 1094185872.

The previous prime is 1641278803. The next prime is 1641278851. The reversal of 1641278817 is 7188721461.

It can be written as a sum of positive squares in only one way, i.e., 880843041 + 760435776 = 29679^2 + 27576^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1641278817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1641278887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 91182148 + ... + 91182165.

Almost surely, 2^1641278817 is an apocalyptic number.

It is an amenable number.

1641278817 is a deficient number, since it is larger than the sum of its proper divisors (729457265).

1641278817 is a wasteful number, since it uses less digits than its factorization.

1641278817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182364319 (or 182364316 counting only the distinct ones).

The product of its digits is 150528, while the sum is 45.

The square root of 1641278817 is about 40512.6994533813. The cubic root of 1641278817 is about 1179.5801477203.

The spelling of 1641278817 in words is "one billion, six hundred forty-one million, two hundred seventy-eight thousand, eight hundred seventeen".