20816280 has 96 divisors (see below), whose sum is σ = 68992560. Its totient is φ = 5441280.

The previous prime is 20816261. The next prime is 20816281. The reversal of 20816280 is 8261802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20816281) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18535 + ... + 19625.

Almost surely, 2^20816280 is an apocalyptic number.

20816280 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 20816280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34496280).

20816280 is an abundant number, since it is smaller than the sum of its proper divisors (48176280).

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

20816280 is a wasteful number, since it uses less digits than its factorization.

20816280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1161 (or 1154 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 20816280 is about 4562.4861643626. The cubic root of 20816280 is about 275.0855050918.

The spelling of 20816280 in words is "twenty million, eight hundred sixteen thousand, two hundred eighty".