20128499 has 16 divisors (see below), whose sum is σ = 21500640. Its totient is φ = 18819840.

The previous prime is 20128487. The next prime is 20128501. The reversal of 20128499 is 99482102.

It is a cyclic number.

It is not a de Polignac number, because 20128499 - 2⁴ = 20128483 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20128439) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 128129 + ... + 128285.

It is an arithmetic number, because the mean of its divisors is an integer number (1343790).

Almost surely, 2^20128499 is an apocalyptic number.

20128499 is a deficient number, since it is larger than the sum of its proper divisors (1372141).

20128499 is a wasteful number, since it uses less digits than its factorization.

20128499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310.

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 20128499 is about 4486.4795775753. The cubic root of 20128499 is about 272.0218543210.

The spelling of 20128499 in words is "twenty million, one hundred twenty-eight thousand, four hundred ninety-nine".