20398255 has 4 divisors (see below), whose sum is σ = 24477912. Its totient is φ = 16318600.

The previous prime is 20398243. The next prime is 20398277. The reversal of 20398255 is 55289302.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20398255 - 2⁷ = 20398127 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20398255.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 2039821 + ... + 2039830.

It is an arithmetic number, because the mean of its divisors is an integer number (6119478).

Almost surely, 2^20398255 is an apocalyptic number.

20398255 is a deficient number, since it is larger than the sum of its proper divisors (4079657).

20398255 is an equidigital number, since it uses as much as digits as its factorization.

20398255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4079656.

The product of its (nonzero) digits is 21600, while the sum is 34.

The square root of 20398255 is about 4516.4427373764. The cubic root of 20398255 is about 273.2316504915.

The spelling of 20398255 in words is "twenty million, three hundred ninety-eight thousand, two hundred fifty-five".