20428815 has 32 divisors (see below), whose sum is σ = 37760256. Its totient is φ = 9320960.

The previous prime is 20428801. The next prime is 20428817. The reversal of 20428815 is 51882402.

It is not a de Polignac number, because 20428815 - 2⁴ = 20428799 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20428817) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 837 + ... + 6446.

It is an arithmetic number, because the mean of its divisors is an integer number (1180008).

Almost surely, 2^20428815 is an apocalyptic number.

20428815 is a deficient number, since it is larger than the sum of its proper divisors (17331441).

20428815 is a wasteful number, since it uses less digits than its factorization.

20428815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7319.

The product of its (nonzero) digits is 5120, while the sum is 30.

The square root of 20428815 is about 4519.8246647409. The cubic root of 20428815 is about 273.3680313212.

The spelling of 20428815 in words is "twenty million, four hundred twenty-eight thousand, eight hundred fifteen".