64545409 has 2 divisors, whose sum is σ = 64545410. Its totient is φ = 64545408.

The previous prime is 64545389. The next prime is 64545433. The reversal of 64545409 is 90454546.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 63600625 + 944784 = 7975^2 + 972^2 .

It is a cyclic number.

It is not a de Polignac number, because 64545409 - 2²³ = 56156801 is a prime.

It is a super-2 number, since 2×64545409² = 8332219645954562, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (64545479) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32272704 + 32272705.

It is an arithmetic number, because the mean of its divisors is an integer number (32272705).

Almost surely, 2^64545409 is an apocalyptic number.

It is an amenable number.

64545409 is a deficient number, since it is larger than the sum of its proper divisors (1).

64545409 is an equidigital number, since it uses as much as digits as its factorization.

64545409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 86400, while the sum is 37.

The square root of 64545409 is about 8034.0157455658. The cubic root of 64545409 is about 401.1330561787.

The spelling of 64545409 in words is "sixty-four million, five hundred forty-five thousand, four hundred nine".