20901289 has 2 divisors, whose sum is σ = 20901290. Its totient is φ = 20901288.

The previous prime is 20901277. The next prime is 20901299. The reversal of 20901289 is 98210902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16933225 + 3968064 = 4115^2 + 1992^2 .

It is a cyclic number.

It is not a de Polignac number, because 20901289 - 2¹³ = 20893097 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20901289.

It is not a weakly prime, because it can be changed into another prime (20901259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10450644 + 10450645.

It is an arithmetic number, because the mean of its divisors is an integer number (10450645).

Almost surely, 2^20901289 is an apocalyptic number.

It is an amenable number.

20901289 is a deficient number, since it is larger than the sum of its proper divisors (1).

20901289 is an equidigital number, since it uses as much as digits as its factorization.

20901289 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 20901289 is about 4571.7927555829. The cubic root of 20901289 is about 275.4594589243.

The spelling of 20901289 in words is "twenty million, nine hundred one thousand, two hundred eighty-nine".