20838720 has 168 divisors, whose sum is σ = 77138784. Its totient is φ = 4752384.

The previous prime is 20838707. The next prime is 20838721. The reversal of 20838720 is 2783802.

It is a tau number, because it is divible by the number of its divisors (168).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20838721) 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 23 ways as a sum of consecutive naturals, for example, 46819 + ... + 47261.

Almost surely, 2^20838720 is an apocalyptic number.

20838720 is a gapful number since it is divisible by the number (20) 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 20838720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38569392).

20838720 is an abundant number, since it is smaller than the sum of its proper divisors (56300064).

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

20838720 is a wasteful number, since it uses less digits than its factorization.

20838720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 477 (or 460 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 20838720 is about 4564.9446875072. The cubic root of 20838720 is about 275.1843172062.

The spelling of 20838720 in words is "twenty million, eight hundred thirty-eight thousand, seven hundred twenty".