1966661 has 8 divisors (see below), whose sum is σ = 2108544. Its totient is φ = 1829520.

The previous prime is 1966619. The next prime is 1966663. The reversal of 1966661 is 1666691.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1966661 - 2⁶ = 1966597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1966663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 305 + ... + 2006.

It is an arithmetic number, because the mean of its divisors is an integer number (263568).

2^1966661 is an apocalyptic number.

It is an amenable number.

1966661 is a deficient number, since it is larger than the sum of its proper divisors (141883).

1966661 is a wasteful number, since it uses less digits than its factorization.

1966661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2371.

The product of its digits is 11664, while the sum is 35.

The square root of 1966661 is about 1402.3769108196. The cubic root of 1966661 is about 125.2881034610.

The spelling of 1966661 in words is "one million, nine hundred sixty-six thousand, six hundred sixty-one".