1616322581 has 2 divisors, whose sum is σ = 1616322582. Its totient is φ = 1616322580.

The previous prime is 1616322577. The next prime is 1616322607. The reversal of 1616322581 is 1852236161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1600720081 + 15602500 = 40009^2 + 3950^2 .

It is a cyclic number.

It is not a de Polignac number, because 1616322581 - 2² = 1616322577 is a prime.

It is a super-2 number, since 2×1616322581² = 5224997371701003122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1616322781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 808161290 + 808161291.

It is an arithmetic number, because the mean of its divisors is an integer number (808161291).

Almost surely, 2^1616322581 is an apocalyptic number.

It is an amenable number.

1616322581 is a deficient number, since it is larger than the sum of its proper divisors (1).

1616322581 is an equidigital number, since it uses as much as digits as its factorization.

1616322581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17280, while the sum is 35.

The square root of 1616322581 is about 40203.5145354234. The cubic root of 1616322581 is about 1173.5709395176.

The spelling of 1616322581 in words is "one billion, six hundred sixteen million, three hundred twenty-two thousand, five hundred eighty-one".