20985426 has 128 divisors (see below), whose sum is σ = 59904000. Its totient is φ = 5397840.

The previous prime is 20985421. The next prime is 20985439. The reversal of 20985426 is 62458902.

20985426 = T₁₆₄ + T₁₆₅ + ... + T₅₀₆.

It is a happy number.

20985426 is a `hidden beast` number, since 20 + 98 + 542 + 6 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20985421) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 203691 + ... + 203793.

It is an arithmetic number, because the mean of its divisors is an integer number (468000).

Almost surely, 2^20985426 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20985426, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29952000).

20985426 is an abundant number, since it is smaller than the sum of its proper divisors (38918574).

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

20985426 is a wasteful number, since it uses less digits than its factorization.

20985426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146 (or 126 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 20985426 is about 4580.9852652022. The cubic root of 20985426 is about 275.8285797554.

The spelling of 20985426 in words is "twenty million, nine hundred eighty-five thousand, four hundred twenty-six".