20649804 has 48 divisors (see below), whose sum is σ = 56356608. Its totient is φ = 5761728.

The previous prime is 20649803. The next prime is 20649809. The reversal of 20649804 is 40894602.

It is not an unprimeable number, because it can be changed into a prime (20649803) 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 15 ways as a sum of consecutive naturals, for example, 754 + ... + 6470.

It is an arithmetic number, because the mean of its divisors is an integer number (1174096).

Almost surely, 2^20649804 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 20649804, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28178304).

20649804 is an abundant number, since it is smaller than the sum of its proper divisors (35706804).

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

20649804 is a wasteful number, since it uses less digits than its factorization.

20649804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5774 (or 5772 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 20649804 is about 4544.2055411260. The cubic root of 20649804 is about 274.3502190490.

The spelling of 20649804 in words is "twenty million, six hundred forty-nine thousand, eight hundred four".