17660861381 has 2 divisors, whose sum is σ = 17660861382. Its totient is φ = 17660861380.

The previous prime is 17660861369. The next prime is 17660861411. The reversal of 17660861381 is 18316806671.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15831930625 + 1828930756 = 125825^2 + 42766^2 .

It is an emirp because it is prime and its reverse (18316806671) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-17660861381 is a prime.

It is a super-2 number, since 2×17660861381² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (17660861321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8830430690 + 8830430691.

It is an arithmetic number, because the mean of its divisors is an integer number (8830430691).

Almost surely, 2^17660861381 is an apocalyptic number.

It is an amenable number.

17660861381 is a deficient number, since it is larger than the sum of its proper divisors (1).

17660861381 is an equidigital number, since it uses as much as digits as its factorization.

17660861381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 290304, while the sum is 47.

The spelling of 17660861381 in words is "seventeen billion, six hundred sixty million, eight hundred sixty-one thousand, three hundred eighty-one".