64481909 has 2 divisors, whose sum is σ = 64481910. Its totient is φ = 64481908.

The previous prime is 64481899. The next prime is 64481947. The reversal of 64481909 is 90918446.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 58216900 + 6265009 = 7630^2 + 2503^2 .

It is a cyclic number.

It is not a de Polignac number, because 64481909 - 2²⁴ = 47704693 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64481009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32240954 + 32240955.

It is an arithmetic number, because the mean of its divisors is an integer number (32240955).

Almost surely, 2^64481909 is an apocalyptic number.

It is an amenable number.

64481909 is a deficient number, since it is larger than the sum of its proper divisors (1).

64481909 is an equidigital number, since it uses as much as digits as its factorization.

64481909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 64481909 is about 8030.0628266534. The cubic root of 64481909 is about 401.0014676472.

The spelling of 64481909 in words is "sixty-four million, four hundred eighty-one thousand, nine hundred nine".