1668564 has 18 divisors (see below), whose sum is σ = 4217850. Its totient is φ = 556176.

The previous prime is 1668553. The next prime is 1668587. The reversal of 1668564 is 4658661.

It can be written as a sum of positive squares in only one way, i.e., 1192464 + 476100 = 1092^2 + 690^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 46349 = 1668564 / (1 + 6 + 6 + 8 + 5 + 6 + 4).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 23139 + ... + 23210.

It is an arithmetic number, because the mean of its divisors is an integer number (234325).

2^1668564 is an apocalyptic number.

It is an amenable number.

1668564 is an abundant number, since it is smaller than the sum of its proper divisors (2549286).

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

1668564 is a wasteful number, since it uses less digits than its factorization.

1668564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46359 (or 46354 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 1668564 is about 1291.7290737612. The cubic root of 1668564 is about 118.6080838362.

The spelling of 1668564 in words is "one million, six hundred sixty-eight thousand, five hundred sixty-four".