20839680 has 216 divisors, whose sum is σ = 75889632. Its totient is φ = 5474304.

The previous prime is 20839667. The next prime is 20839691. The reversal of 20839680 is 8693802.

It is a tau number, because it is divible by the number of its divisors (216).

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 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, 311007 + ... + 311073.

Almost surely, 2^20839680 is an apocalyptic number.

20839680 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 20839680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37944816).

20839680 is an abundant number, since it is smaller than the sum of its proper divisors (55049952).

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

20839680 is an frugal number, since it uses more digits than its factorization.

20839680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103 (or 77 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 20839680 is about 4565.0498354344. The cubic root of 20839680 is about 275.1885428798.

The spelling of 20839680 in words is "twenty million, eight hundred thirty-nine thousand, six hundred eighty".