20128815 has 24 divisors (see below), whose sum is σ = 39874848. Its totient is φ = 9201600.

The previous prime is 20128793. The next prime is 20128837. The reversal of 20128815 is 51882102.

It is an interprime number because it is at equal distance from previous prime (20128793) and next prime (20128837).

It is not a de Polignac number, because 20128815 - 2⁵ = 20128783 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 31636 + ... + 32265.

It is an arithmetic number, because the mean of its divisors is an integer number (1661452).

Almost surely, 2^20128815 is an apocalyptic number.

20128815 is a deficient number, since it is larger than the sum of its proper divisors (19746033).

20128815 is a wasteful number, since it uses less digits than its factorization.

20128815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63919 (or 63916 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The square root of 20128815 is about 4486.5147943588. The cubic root of 20128815 is about 272.0232778161.

The spelling of 20128815 in words is "twenty million, one hundred twenty-eight thousand, eight hundred fifteen".