20428277 has 2 divisors, whose sum is σ = 20428278. Its totient is φ = 20428276.

The previous prime is 20428273. The next prime is 20428283. The reversal of 20428277 is 77282402.

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., 12666481 + 7761796 = 3559^2 + 2786^2 .

It is a cyclic number.

It is not a de Polignac number, because 20428277 - 2² = 20428273 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20428273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10214138 + 10214139.

It is an arithmetic number, because the mean of its divisors is an integer number (10214139).

Almost surely, 2^20428277 is an apocalyptic number.

It is an amenable number.

20428277 is a deficient number, since it is larger than the sum of its proper divisors (1).

20428277 is an equidigital number, since it uses as much as digits as its factorization.

20428277 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12544, while the sum is 32.

The square root of 20428277 is about 4519.7651487660. The cubic root of 20428277 is about 273.3656315525.

The spelling of 20428277 in words is "twenty million, four hundred twenty-eight thousand, two hundred seventy-seven".