20255689 has 2 divisors, whose sum is σ = 20255690. Its totient is φ = 20255688.

The previous prime is 20255657. The next prime is 20255723. The reversal of 20255689 is 98655202.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11799225 + 8456464 = 3435^2 + 2908^2 .

It is a cyclic number.

It is not a de Polignac number, because 20255689 - 2⁵ = 20255657 is a prime.

It is not a weakly prime, because it can be changed into another prime (20255639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10127844 + 10127845.

It is an arithmetic number, because the mean of its divisors is an integer number (10127845).

Almost surely, 2^20255689 is an apocalyptic number.

It is an amenable number.

20255689 is a deficient number, since it is larger than the sum of its proper divisors (1).

20255689 is an equidigital number, since it uses as much as digits as its factorization.

20255689 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 43200, while the sum is 37.

The square root of 20255689 is about 4500.6320667213. The cubic root of 20255689 is about 272.5936114708.

The spelling of 20255689 in words is "twenty million, two hundred fifty-five thousand, six hundred eighty-nine".