1668636 has 18 divisors (see below), whose sum is σ = 4218032. Its totient is φ = 556200.

The previous prime is 1668629. The next prime is 1668647. The reversal of 1668636 is 6368661.

1668636 = T₁₁₉ + T₁₂₀ + ... + T₂₂₆.

1668636 is a `hidden beast` number, since 16 + 6 + 8 + 636 = 666.

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

It is a super-2 number, since 2×1668636² = 5568692200992, which contains 22 as substring.

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: 46351 = 1668636 / (1 + 6 + 6 + 8 + 6 + 3 + 6).

It is an Ulam number.

It is a nialpdrome in base 6.

It is a self number, because there is not a number n which added to its sum of digits gives 1668636.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 23140 + ... + 23211.

2^1668636 is an apocalyptic number.

It is an amenable number.

1668636 is an abundant number, since it is smaller than the sum of its proper divisors (2549396).

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

1668636 is a wasteful number, since it uses less digits than its factorization.

1668636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46361 (or 46356 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 1668636 is about 1291.7569430818. The cubic root of 1668636 is about 118.6097898259.

It can be divided in two parts, 1668 and 636, that added together give a square (2304 = 48²).

The spelling of 1668636 in words is "one million, six hundred sixty-eight thousand, six hundred thirty-six".