20705616 has 60 divisors (see below), whose sum is σ = 59062068. Its totient is φ = 6769152.

The previous prime is 20705593. The next prime is 20705621. The reversal of 20705616 is 61650702.

It can be written as a sum of positive squares in 2 ways, for example, as 18455616 + 2250000 = 4296^2 + 1500^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20705616.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 6276 + ... + 8988.

Almost surely, 2^20705616 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 20705616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29531034).

20705616 is an abundant number, since it is smaller than the sum of its proper divisors (38356452).

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

20705616 is a wasteful number, since it uses less digits than its factorization.

20705616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2780 (or 2771 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

The square root of 20705616 is about 4550.3424046988. The cubic root of 20705616 is about 274.5971666722.

It can be divided in two parts, 20705 and 616, that added together give a triangular number (21321 = T₂₀₆).

The spelling of 20705616 in words is "twenty million, seven hundred five thousand, six hundred sixteen".