1661646 has 16 divisors (see below), whose sum is σ = 3798144. Its totient is φ = 474744.

The previous prime is 1661641. The next prime is 1661659. The reversal of 1661646 is 6461661.

It is a super-2 number, since 2×1661646² = 5522134858632, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661641) 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, 19740 + ... + 19823.

It is an arithmetic number, because the mean of its divisors is an integer number (237384).

2^1661646 is an apocalyptic number.

1661646 is an abundant number, since it is smaller than the sum of its proper divisors (2136498).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1661646 is a wasteful number, since it uses less digits than its factorization.

1661646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39575.

The product of its digits is 5184, while the sum is 30.

The square root of 1661646 is about 1289.0484862875. The cubic root of 1661646 is about 118.4439372329.

The spelling of 1661646 in words is "one million, six hundred sixty-one thousand, six hundred forty-six".