20919280 has 40 divisors (see below), whose sum is σ = 49104000. Its totient is φ = 8287488.

The previous prime is 20919271. The next prime is 20919281. The reversal of 20919280 is 8291902.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20919281) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7521 + ... + 9919.

It is an arithmetic number, because the mean of its divisors is an integer number (1227600).

Almost surely, 2^20919280 is an apocalyptic number.

20919280 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 20919280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24552000).

20919280 is an abundant number, since it is smaller than the sum of its proper divisors (28184720).

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

20919280 is a wasteful number, since it uses less digits than its factorization.

20919280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2521 (or 2515 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 20919280 is about 4573.7599412300. The cubic root of 20919280 is about 275.5384711148.

The spelling of 20919280 in words is "twenty million, nine hundred nineteen thousand, two hundred eighty".