20285515 has 4 divisors (see below), whose sum is σ = 24342624. Its totient is φ = 16228408.

The previous prime is 20285497. The next prime is 20285519. The reversal of 20285515 is 51558202.

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

It is a cyclic number.

It is not a de Polignac number, because 20285515 - 2⁹ = 20285003 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20285519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2028547 + ... + 2028556.

It is an arithmetic number, because the mean of its divisors is an integer number (6085656).

Almost surely, 2^20285515 is an apocalyptic number.

20285515 is a deficient number, since it is larger than the sum of its proper divisors (4057109).

20285515 is an equidigital number, since it uses as much as digits as its factorization.

20285515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4057108.

The product of its (nonzero) digits is 4000, while the sum is 28.

The square root of 20285515 is about 4503.9443824275. The cubic root of 20285515 is about 272.7273416330.

The spelling of 20285515 in words is "twenty million, two hundred eighty-five thousand, five hundred fifteen".