20825784 has 72 divisors (see below), whose sum is σ = 65622960. Its totient is φ = 5949216.

The previous prime is 20825771. The next prime is 20825801. The reversal of 20825784 is 48752802.

It is a happy number.

20825784 is a `hidden beast` number, since 2 + 0 + 82 + 578 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 577 + ... + 6479.

It is an arithmetic number, because the mean of its divisors is an integer number (911430).

Almost surely, 2^20825784 is an apocalyptic number.

20825784 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20825784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32811480).

20825784 is an abundant number, since it is smaller than the sum of its proper divisors (44797176).

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

20825784 is a wasteful number, since it uses less digits than its factorization.

20825784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5929 (or 5915 counting only the distinct ones).

The product of its (nonzero) digits is 35840, while the sum is 36.

The square root of 20825784 is about 4563.5275829121. The cubic root of 20825784 is about 275.1273635932.

It can be divided in two parts, 20825 and 784, that added together give a square (21609 = 147²).

The spelling of 20825784 in words is "twenty million, eight hundred twenty-five thousand, seven hundred eighty-four".