20188668 has 12 divisors (see below), whose sum is σ = 47106920. Its totient is φ = 6729552.

The previous prime is 20188667. The next prime is 20188703. The reversal of 20188668 is 86688102.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×20188668² = 815164631228448, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20188667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 841183 + ... + 841206.

Almost surely, 2^20188668 is an apocalyptic number.

It is an amenable number.

20188668 is an abundant number, since it is smaller than the sum of its proper divisors (26918252).

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

20188668 is a wasteful number, since it uses less digits than its factorization.

20188668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1682396 (or 1682394 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 39.

The square root of 20188668 is about 4493.1801655398. The cubic root of 20188668 is about 272.2926312823.

The spelling of 20188668 in words is "twenty million, one hundred eighty-eight thousand, six hundred sixty-eight".