3709627616581 has 2 divisors, whose sum is σ = 3709627616582. Its totient is φ = 3709627616580.

The previous prime is 3709627616579. The next prime is 3709627616641. The reversal of 3709627616581 is 1856167269073.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2367120717025 + 1342506899556 = 1538545^2 + 1158666^2 .

It is a cyclic number.

It is not a de Polignac number, because 3709627616581 - 2¹ = 3709627616579 is a prime.

It is a super-2 number, since 2×3709627616581² (a number of 26 digits) contains 22 as substring.

Together with 3709627616579, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3709627616501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1854813808290 + 1854813808291.

It is an arithmetic number, because the mean of its divisors is an integer number (1854813808291).

Almost surely, 2^{3709627616581} is an apocalyptic number.

It is an amenable number.

3709627616581 is a deficient number, since it is larger than the sum of its proper divisors (1).

3709627616581 is an equidigital number, since it uses as much as digits as its factorization.

3709627616581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 22861440, while the sum is 61.

The spelling of 3709627616581 in words is "three trillion, seven hundred nine billion, six hundred twenty-seven million, six hundred sixteen thousand, five hundred eighty-one".