20128799 has 4 divisors (see below), whose sum is σ = 21312864. Its totient is φ = 18944736.

The previous prime is 20128793. The next prime is 20128837. The reversal of 20128799 is 99782102.

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 20128799 - 2⁴ = 20128783 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20128793) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 592007 + ... + 592040.

It is an arithmetic number, because the mean of its divisors is an integer number (5328216).

Almost surely, 2^20128799 is an apocalyptic number.

20128799 is a deficient number, since it is larger than the sum of its proper divisors (1184065).

20128799 is a wasteful number, since it uses less digits than its factorization.

20128799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1184064.

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 20128799 is about 4486.5130112371. The cubic root of 20128799 is about 272.0232057407.

The spelling of 20128799 in words is "twenty million, one hundred twenty-eight thousand, seven hundred ninety-nine".