20858736 has 40 divisors (see below), whose sum is σ = 54421120. Its totient is φ = 6883776.

The previous prime is 20858731. The next prime is 20858749. The reversal of 20858736 is 63785802.

It is a junction number, because it is equal to n+sod(n) for n = 20858694 and 20858703.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20858731) 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 7 ways as a sum of consecutive naturals, for example, 2835 + ... + 7053.

It is an arithmetic number, because the mean of its divisors is an integer number (1360528).

Almost surely, 2^20858736 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 20858736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27210560).

20858736 is an abundant number, since it is smaller than the sum of its proper divisors (33562384).

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

20858736 is a wasteful number, since it uses less digits than its factorization.

20858736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4333 (or 4327 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 39.

The square root of 20858736 is about 4567.1365208410. The cubic root of 20858736 is about 275.2723956597.

The spelling of 20858736 in words is "twenty million, eight hundred fifty-eight thousand, seven hundred thirty-six".