20289618 has 48 divisors (see below), whose sum is σ = 46500480. Its totient is φ = 6383328.

The previous prime is 20289583. The next prime is 20289623. The reversal of 20289618 is 81698202.

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 23 ways as a sum of consecutive naturals, for example, 24121 + ... + 24947.

It is an arithmetic number, because the mean of its divisors is an integer number (968760).

Almost surely, 2^20289618 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20289618, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23250240).

20289618 is an abundant number, since it is smaller than the sum of its proper divisors (26210862).

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

20289618 is a wasteful number, since it uses less digits than its factorization.

20289618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 911 (or 908 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 20289618 is about 4504.3998490365. The cubic root of 20289618 is about 272.7457279026.

The spelling of 20289618 in words is "twenty million, two hundred eighty-nine thousand, six hundred eighteen".