1606015666 has 4 divisors (see below), whose sum is σ = 2409023502. Its totient is φ = 803007832.

The previous prime is 1606015651. The next prime is 1606015681. The reversal of 1606015666 is 6665106061.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6665106061 = 66107 ⋅100823.

It is an interprime number because it is at equal distance from previous prime (1606015651) and next prime (1606015681).

It can be written as a sum of positive squares in only one way, i.e., 1605685041 + 330625 = 40071^2 + 575^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 401503915 + ... + 401503918.

Almost surely, 2^1606015666 is an apocalyptic number.

1606015666 is a deficient number, since it is larger than the sum of its proper divisors (803007836).

1606015666 is an equidigital number, since it uses as much as digits as its factorization.

1606015666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 803007835.

The product of its (nonzero) digits is 38880, while the sum is 37.

The square root of 1606015666 is about 40075.1252774087. The cubic root of 1606015666 is about 1171.0710882202.

The spelling of 1606015666 in words is "one billion, six hundred six million, fifteen thousand, six hundred sixty-six".