20121608 has 64 divisors (see below), whose sum is σ = 45360000. Its totient is φ = 8266752.

The previous prime is 20121581. The next prime is 20121623. The reversal of 20121608 is 80612102.

It is a self number, because there is not a number n which added to its sum of digits gives 20121608.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33293 + ... + 33891.

It is an arithmetic number, because the mean of its divisors is an integer number (708750).

Almost surely, 2^20121608 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20121608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22680000).

20121608 is an abundant number, since it is smaller than the sum of its proper divisors (25238392).

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

20121608 is a wasteful number, since it uses less digits than its factorization.

20121608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 654 (or 650 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 20121608 is about 4485.7115377608. The cubic root of 20121608 is about 271.9908085129.

The spelling of 20121608 in words is "twenty million, one hundred twenty-one thousand, six hundred eight".