1626116581 has 2 divisors, whose sum is σ = 1626116582. Its totient is φ = 1626116580.

The previous prime is 1626116579. The next prime is 1626116627. The reversal of 1626116581 is 1856116261.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1322485956 + 303630625 = 36366^2 + 17425^2 .

It is a cyclic number.

It is not a de Polignac number, because 1626116581 - 2¹ = 1626116579 is a prime.

It is a super-2 number, since 2×1626116581² = 5288510270006259122, which contains 22 as substring.

Together with 1626116579, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1626116581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1626116551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 813058290 + 813058291.

It is an arithmetic number, because the mean of its divisors is an integer number (813058291).

Almost surely, 2^1626116581 is an apocalyptic number.

It is an amenable number.

1626116581 is a deficient number, since it is larger than the sum of its proper divisors (1).

1626116581 is an equidigital number, since it uses as much as digits as its factorization.

1626116581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17280, while the sum is 37.

The square root of 1626116581 is about 40325.1358460204. The cubic root of 1626116581 is about 1175.9365597092.

The spelling of 1626116581 in words is "one billion, six hundred twenty-six million, one hundred sixteen thousand, five hundred eighty-one".