64436209 has 2 divisors, whose sum is σ = 64436210. Its totient is φ = 64436208.

The previous prime is 64436189. The next prime is 64436213. The reversal of 64436209 is 90263446.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62362609 + 2073600 = 7897^2 + 1440^2 .

It is a cyclic number.

It is not a de Polignac number, because 64436209 - 2¹⁹ = 63911921 is a prime.

It is not a weakly prime, because it can be changed into another prime (64436299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32218104 + 32218105.

It is an arithmetic number, because the mean of its divisors is an integer number (32218105).

Almost surely, 2^64436209 is an apocalyptic number.

It is an amenable number.

64436209 is a deficient number, since it is larger than the sum of its proper divisors (1).

64436209 is an equidigital number, since it uses as much as digits as its factorization.

64436209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 34.

The square root of 64436209 is about 8027.2167654798. The cubic root of 64436209 is about 400.9067118809.

The spelling of 64436209 in words is "sixty-four million, four hundred thirty-six thousand, two hundred nine".