20028137 has 4 divisors (see below), whose sum is σ = 20569476. Its totient is φ = 19486800.

The previous prime is 20028121. The next prime is 20028179. The reversal of 20028137 is 73182002.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14055001 + 5973136 = 3749^2 + 2444^2 .

It is a cyclic number.

It is not a de Polignac number, because 20028137 - 2⁴ = 20028121 is a prime.

It is a super-2 number, since 2×20028137² = 802252543381538, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20028637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 270614 + ... + 270687.

It is an arithmetic number, because the mean of its divisors is an integer number (5142369).

Almost surely, 2^20028137 is an apocalyptic number.

It is an amenable number.

20028137 is a deficient number, since it is larger than the sum of its proper divisors (541339).

20028137 is an equidigital number, since it uses as much as digits as its factorization.

20028137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 541338.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 20028137 is about 4475.2806615898. The cubic root of 20028137 is about 271.5689946264.

The spelling of 20028137 in words is "twenty million, twenty-eight thousand, one hundred thirty-seven".