20890255 has 4 divisors (see below), whose sum is σ = 25068312. Its totient is φ = 16712200.

The previous prime is 20890241. The next prime is 20890277. The reversal of 20890255 is 55209802.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 55209802 = 2 ⋅27604901.

It is not a de Polignac number, because 20890255 - 2⁵ = 20890223 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2089021 + ... + 2089030.

It is an arithmetic number, because the mean of its divisors is an integer number (6267078).

Almost surely, 2^20890255 is an apocalyptic number.

20890255 is a deficient number, since it is larger than the sum of its proper divisors (4178057).

20890255 is an equidigital number, since it uses as much as digits as its factorization.

20890255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4178056.

The product of its (nonzero) digits is 7200, while the sum is 31.

The square root of 20890255 is about 4570.5858486632. The cubic root of 20890255 is about 275.4109777887.

The spelling of 20890255 in words is "twenty million, eight hundred ninety thousand, two hundred fifty-five".