20828340 has 240 divisors, whose sum is σ = 75132288. Its totient is φ = 4790016.

The previous prime is 20828333. The next prime is 20828371. The reversal of 20828340 is 4382802.

It is a Harshad number since it is a multiple of its sum of digits (27).

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 79 ways as a sum of consecutive naturals, for example, 484359 + ... + 484401.

Almost surely, 2^20828340 is an apocalyptic number.

20828340 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 20828340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37566144).

20828340 is an abundant number, since it is smaller than the sum of its proper divisors (54303948).

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

20828340 is a wasteful number, since it uses less digits than its factorization.

20828340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100 (or 89 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 20828340 is about 4563.8076208359. The cubic root of 20828340 is about 275.1386188201.

The spelling of 20828340 in words is "twenty million, eight hundred twenty-eight thousand, three hundred forty".