1606605181 has 2 divisors, whose sum is σ = 1606605182. Its totient is φ = 1606605180.

The previous prime is 1606605149. The next prime is 1606605199. The reversal of 1606605181 is 1815066061.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 963171225 + 643433956 = 31035^2 + 25366^2 .

It is an emirp because it is prime and its reverse (1815066061) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1606605181 - 2⁵ = 1606605149 is a prime.

It is a super-2 number, since 2×1606605181² = 5162360415232085522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1606602181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 803302590 + 803302591.

It is an arithmetic number, because the mean of its divisors is an integer number (803302591).

Almost surely, 2^1606605181 is an apocalyptic number.

It is an amenable number.

1606605181 is a deficient number, since it is larger than the sum of its proper divisors (1).

1606605181 is an equidigital number, since it uses as much as digits as its factorization.

1606605181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 34.

The square root of 1606605181 is about 40082.4797261846. The cubic root of 1606605181 is about 1171.2143577899.

The spelling of 1606605181 in words is "one billion, six hundred six million, six hundred five thousand, one hundred eighty-one".