20028281 has 16 divisors (see below), whose sum is σ = 24858624. Its totient is φ = 15712704.

The previous prime is 20028277. The next prime is 20028287. The reversal of 20028281 is 18282002.

It is not a de Polignac number, because 20028281 - 2² = 20028277 is a prime.

It is a super-2 number, since 2×20028281² = 802264079629922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20028287) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10691 + ... + 12423.

It is an arithmetic number, because the mean of its divisors is an integer number (1553664).

Almost surely, 2^20028281 is an apocalyptic number.

It is an amenable number.

20028281 is a deficient number, since it is larger than the sum of its proper divisors (4830343).

20028281 is a wasteful number, since it uses less digits than its factorization.

20028281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1880.

The product of its (nonzero) digits is 512, while the sum is 23.

The square root of 20028281 is about 4475.2967499374. The cubic root of 20028281 is about 271.5696454747.

The spelling of 20028281 in words is "twenty million, twenty-eight thousand, two hundred eighty-one".