1966641 has 4 divisors (see below), whose sum is σ = 2622192. Its totient is φ = 1311092.

The previous prime is 1966619. The next prime is 1966663. The reversal of 1966641 is 1466691.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1466691 = 3 ⋅488897.

It is an interprime number because it is at equal distance from previous prime (1966619) and next prime (1966663).

It is a cyclic number.

It is not a de Polignac number, because 1966641 - 2¹¹ = 1964593 is a prime.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (1966681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 327771 + ... + 327776.

It is an arithmetic number, because the mean of its divisors is an integer number (655548).

2^1966641 is an apocalyptic number.

It is an amenable number.

1966641 is a deficient number, since it is larger than the sum of its proper divisors (655551).

1966641 is an equidigital number, since it uses as much as digits as its factorization.

1966641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 655550.

The product of its digits is 7776, while the sum is 33.

The square root of 1966641 is about 1402.3697800509. The cubic root of 1966641 is about 125.2876787529.

The spelling of 1966641 in words is "one million, nine hundred sixty-six thousand, six hundred forty-one".