3721318561 has 2 divisors, whose sum is σ = 3721318562. Its totient is φ = 3721318560.

The previous prime is 3721318543. The next prime is 3721318571. The reversal of 3721318561 is 1658131273.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2379488400 + 1341830161 = 48780^2 + 36631^2 .

It is a cyclic number.

It is not a de Polignac number, because 3721318561 - 2²⁷ = 3587100833 is a prime.

It is a super-2 number, since 2×3721318561² = 27696423664886221442, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 3721318561.

It is not a weakly prime, because it can be changed into another prime (3721318501) 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 as a sum of consecutive naturals, namely, 1860659280 + 1860659281.

It is an arithmetic number, because the mean of its divisors is an integer number (1860659281).

Almost surely, 2^3721318561 is an apocalyptic number.

It is an amenable number.

3721318561 is a deficient number, since it is larger than the sum of its proper divisors (1).

3721318561 is an equidigital number, since it uses as much as digits as its factorization.

3721318561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 37.

The square root of 3721318561 is about 61002.6110998538. The cubic root of 3721318561 is about 1549.6452273019.

The spelling of 3721318561 in words is "three billion, seven hundred twenty-one million, three hundred eighteen thousand, five hundred sixty-one".