1661568 has 32 divisors (see below), whose sum is σ = 4414560. Its totient is φ = 553728.

The previous prime is 1661567. The next prime is 1661587. The reversal of 1661568 is 8651661.

It is a tau number, because it is divible by the number of its divisors (32).

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (1661567) 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, 1780 + ... + 2547.

It is an arithmetic number, because the mean of its divisors is an integer number (137955).

2^1661568 is an apocalyptic number.

It is an amenable number.

1661568 is an abundant number, since it is smaller than the sum of its proper divisors (2752992).

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

1661568 is an equidigital number, since it uses as much as digits as its factorization.

1661568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4344 (or 4332 counting only the distinct ones).

The product of its digits is 8640, while the sum is 33.

The square root of 1661568 is about 1289.0182310580. The cubic root of 1661568 is about 118.4420838956.

The spelling of 1661568 in words is "one million, six hundred sixty-one thousand, five hundred sixty-eight".