1630666 has 4 divisors (see below), whose sum is σ = 2446002. Its totient is φ = 815332.

The previous prime is 1630663. The next prime is 1630669. The reversal of 1630666 is 6660361.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6660361 = 191 ⋅34871.

It is an interprime number because it is at equal distance from previous prime (1630663) and next prime (1630669).

It can be written as a sum of positive squares in only one way, i.e., 1625625 + 5041 = 1275^2 + 71^2 .

It is not an unprimeable number, because it can be changed into a prime (1630663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 407665 + ... + 407668.

2^1630666 is an apocalyptic number.

1630666 is a deficient number, since it is larger than the sum of its proper divisors (815336).

1630666 is an equidigital number, since it uses as much as digits as its factorization.

1630666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 815335.

The product of its (nonzero) digits is 3888, while the sum is 28.

The square root of 1630666 is about 1276.9753325730. The cubic root of 1630666 is about 117.7032185698.

The spelling of 1630666 in words is "one million, six hundred thirty thousand, six hundred sixty-six".