20340409 has 2 divisors, whose sum is σ = 20340410. Its totient is φ = 20340408.

The previous prime is 20340407. The next prime is 20340413. The reversal of 20340409 is 90404302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11370384 + 8970025 = 3372^2 + 2995^2 .

It is a cyclic number.

It is not a de Polignac number, because 20340409 - 2¹ = 20340407 is a prime.

Together with 20340407, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 20340409.

It is not a weakly prime, because it can be changed into another prime (20340401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10170204 + 10170205.

It is an arithmetic number, because the mean of its divisors is an integer number (10170205).

Almost surely, 2^20340409 is an apocalyptic number.

It is an amenable number.

20340409 is a deficient number, since it is larger than the sum of its proper divisors (1).

20340409 is an equidigital number, since it uses as much as digits as its factorization.

20340409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 20340409 is about 4510.0342570761. The cubic root of 20340409 is about 272.9731263828.

The spelling of 20340409 in words is "twenty million, three hundred forty thousand, four hundred nine".