20261009 has 2 divisors, whose sum is σ = 20261010. Its totient is φ = 20261008.

The previous prime is 20260997. The next prime is 20261023. The reversal of 20261009 is 90016202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11833600 + 8427409 = 3440^2 + 2903^2 .

It is a cyclic number.

It is not a de Polignac number, because 20261009 - 2⁴ = 20260993 is a prime.

It is not a weakly prime, because it can be changed into another prime (20261039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10130504 + 10130505.

It is an arithmetic number, because the mean of its divisors is an integer number (10130505).

Almost surely, 2^20261009 is an apocalyptic number.

It is an amenable number.

20261009 is a deficient number, since it is larger than the sum of its proper divisors (1).

20261009 is an equidigital number, since it uses as much as digits as its factorization.

20261009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 20261009 is about 4501.2230560149. The cubic root of 20261009 is about 272.6174742495.

The spelling of 20261009 in words is "twenty million, two hundred sixty-one thousand, nine".