20728015 has 32 divisors (see below), whose sum is σ = 32845824. Its totient is φ = 12157440.

The previous prime is 20728009. The next prime is 20728033. The reversal of 20728015 is 51082702.

It is not a de Polignac number, because 20728015 - 2⁹ = 20727503 is a prime.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 4962 + ... + 8128.

It is an arithmetic number, because the mean of its divisors is an integer number (1026432).

Almost surely, 2^20728015 is an apocalyptic number.

20728015 is a deficient number, since it is larger than the sum of its proper divisors (12117809).

20728015 is a wasteful number, since it uses less digits than its factorization.

20728015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3207.

The product of its (nonzero) digits is 1120, while the sum is 25.

The square root of 20728015 is about 4552.8029827789. The cubic root of 20728015 is about 274.6961492438.

The spelling of 20728015 in words is "twenty million, seven hundred twenty-eight thousand, fifteen".