3898437006661 has 2 divisors, whose sum is σ = 3898437006662. Its totient is φ = 3898437006660.

The previous prime is 3898437006647. The next prime is 3898437006679. The reversal of 3898437006661 is 1666007348983.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2407183280100 + 1491253726561 = 1551510^2 + 1221169^2 .

It is an emirp because it is prime and its reverse (1666007348983) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3898437006661 is a prime.

It is a super-2 number, since 2×3898437006661² (a number of 26 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 3898437006661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3898437006361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1949218503330 + 1949218503331.

It is an arithmetic number, because the mean of its divisors is an integer number (1949218503331).

Almost surely, 2^{3898437006661} is an apocalyptic number.

It is an amenable number.

3898437006661 is a deficient number, since it is larger than the sum of its proper divisors (1).

3898437006661 is an equidigital number, since it uses as much as digits as its factorization.

3898437006661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31352832, while the sum is 61.

The spelling of 3898437006661 in words is "three trillion, eight hundred ninety-eight billion, four hundred thirty-seven million, six thousand, six hundred sixty-one".