20287680 has 112 divisors (see below), whose sum is σ = 73639680. Its totient is φ = 4635648.

The previous prime is 20287637. The next prime is 20287703. The reversal of 20287680 is 8678202.

It is a tau number, because it is divible by the number of its divisors (112).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5211 + ... + 8229.

Almost surely, 2^20287680 is an apocalyptic number.

20287680 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 20287680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36819840).

20287680 is an abundant number, since it is smaller than the sum of its proper divisors (53352000).

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

20287680 is a wasteful number, since it uses less digits than its factorization.

20287680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3046 (or 3036 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 33.

The square root of 20287680 is about 4504.1847209012. The cubic root of 20287680 is about 272.7370436903.

The spelling of 20287680 in words is "twenty million, two hundred eighty-seven thousand, six hundred eighty".