1623666 has 32 divisors (see below), whose sum is σ = 3601728. Its totient is φ = 483840.

The previous prime is 1623647. The next prime is 1623667. The reversal of 1623666 is 6663261.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (1623667) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4650 + ... + 4986.

It is an arithmetic number, because the mean of its divisors is an integer number (112554).

2^1623666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1623666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1800864).

1623666 is an abundant number, since it is smaller than the sum of its proper divisors (1978062).

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

1623666 is a wasteful number, since it uses less digits than its factorization.

1623666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 426.

The product of its digits is 7776, while the sum is 30.

The square root of 1623666 is about 1274.2315331210. The cubic root of 1623666 is about 117.5345544969.

It can be divided in two parts, 162 and 3666, that added together give a triangular number (3828 = T₈₇).

The spelling of 1623666 in words is "one million, six hundred twenty-three thousand, six hundred sixty-six".