20347409 has 2 divisors, whose sum is σ = 20347410. Its totient is φ = 20347408.

The previous prime is 20347361. The next prime is 20347427. The reversal of 20347409 is 90474302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18037009 + 2310400 = 4247^2 + 1520^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20347409 is a prime.

It is not a weakly prime, because it can be changed into another prime (20347469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10173704 + 10173705.

It is an arithmetic number, because the mean of its divisors is an integer number (10173705).

Almost surely, 2^20347409 is an apocalyptic number.

It is an amenable number.

20347409 is a deficient number, since it is larger than the sum of its proper divisors (1).

20347409 is an equidigital number, since it uses as much as digits as its factorization.

20347409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 29.

The square root of 20347409 is about 4510.8102376402. The cubic root of 20347409 is about 273.0044366796.

The spelling of 20347409 in words is "twenty million, three hundred forty-seven thousand, four hundred nine".