1663660 has 24 divisors (see below), whose sum is σ = 3519936. Its totient is φ = 660480.

The previous prime is 1663619. The next prime is 1663681. The reversal of 1663660 is 663661.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3645 + ... + 4075.

It is an arithmetic number, because the mean of its divisors is an integer number (146664).

2^1663660 is an apocalyptic number.

1663660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1663660 is an abundant number, since it is smaller than the sum of its proper divisors (1856276).

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

1663660 is a wasteful number, since it uses less digits than its factorization.

1663660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 633 (or 631 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 28.

The square root of 1663660 is about 1289.8294460897. The cubic root of 1663660 is about 118.4917712838.

Subtracting from 1663660 its reverse (663661), we obtain a palindrome (999999).

The spelling of 1663660 in words is "one million, six hundred sixty-three thousand, six hundred sixty".