20010409 has 2 divisors, whose sum is σ = 20010410. Its totient is φ = 20010408.

The previous prime is 20010373. The next prime is 20010443. The reversal of 20010409 is 90401002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19607184 + 403225 = 4428^2 + 635^2 .

It is a cyclic number.

It is not a de Polignac number, because 20010409 - 2⁷ = 20010281 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20010392 and 20010401.

It is not a weakly prime, because it can be changed into another prime (20010209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10005204 + 10005205.

It is an arithmetic number, because the mean of its divisors is an integer number (10005205).

Almost surely, 2^20010409 is an apocalyptic number.

It is an amenable number.

20010409 is a deficient number, since it is larger than the sum of its proper divisors (1).

20010409 is an equidigital number, since it uses as much as digits as its factorization.

20010409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 20010409 is about 4473.2995651979. The cubic root of 20010409 is about 271.4888441140.

It can be divided in two parts, 200 and 10409, that added together give a square (10609 = 103²).

The spelling of 20010409 in words is "twenty million, ten thousand, four hundred nine".