3661557917 has 2 divisors, whose sum is σ = 3661557918. Its totient is φ = 3661557916.

The previous prime is 3661557883. The next prime is 3661557943. The reversal of 3661557917 is 7197551663.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2215961476 + 1445596441 = 47074^2 + 38021^2 .

It is a cyclic number.

It is not a de Polignac number, because 3661557917 - 2⁶ = 3661557853 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3661557967) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1830778958 + 1830778959.

It is an arithmetic number, because the mean of its divisors is an integer number (1830778959).

Almost surely, 2^3661557917 is an apocalyptic number.

It is an amenable number.

3661557917 is a deficient number, since it is larger than the sum of its proper divisors (1).

3661557917 is an equidigital number, since it uses as much as digits as its factorization.

3661557917 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1190700, while the sum is 50.

The square root of 3661557917 is about 60510.8082659619. The cubic root of 3661557917 is about 1541.3051729796.

The spelling of 3661557917 in words is "three billion, six hundred sixty-one million, five hundred fifty-seven thousand, nine hundred seventeen".