20288380 has 24 divisors (see below), whose sum is σ = 48692448. Its totient is φ = 6955968.

The previous prime is 20288339. The next prime is 20288381. The reversal of 20288380 is 8388202.

20288380 = T₂₃₂ + T₂₃₃ + ... + T₅₁₁.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20288381) 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, 72319 + ... + 72598.

It is an arithmetic number, because the mean of its divisors is an integer number (2028852).

Almost surely, 2^20288380 is an apocalyptic number.

20288380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20288380 is an abundant number, since it is smaller than the sum of its proper divisors (28404068).

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

20288380 is a wasteful number, since it uses less digits than its factorization.

20288380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144933 (or 144931 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 31.

The square root of 20288380 is about 4504.2624257474. The cubic root of 20288380 is about 272.7401804665.

The spelling of 20288380 in words is "twenty million, two hundred eighty-eight thousand, three hundred eighty".