20428115 has 4 divisors (see below), whose sum is σ = 24513744. Its totient is φ = 16342488.

The previous prime is 20428069. The next prime is 20428141. The reversal of 20428115 is 51182402.

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 20428115 - 2⁸ = 20427859 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2042807 + ... + 2042816.

It is an arithmetic number, because the mean of its divisors is an integer number (6128436).

Almost surely, 2^20428115 is an apocalyptic number.

20428115 is a deficient number, since it is larger than the sum of its proper divisors (4085629).

20428115 is an equidigital number, since it uses as much as digits as its factorization.

20428115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4085628.

The product of its (nonzero) digits is 640, while the sum is 23.

The square root of 20428115 is about 4519.7472274454. The cubic root of 20428115 is about 273.3649089373.

The spelling of 20428115 in words is "twenty million, four hundred twenty-eight thousand, one hundred fifteen".